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Research involving Lowell Observatory staff 2016
(Articles and chapters)

This is a work ever in progress.

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Years: 2016 Bottom


  1. Thirouin, A., Moskovitz, N., Binzel, R., Christensen, E., DeMeo, F., Person, M., Polishook, D., Thomas, C., Trilling, D., Willman, M., Hinkle, M., Burt, B., Avner, D., Aceituno, F., 2016, AJ, 152, 163, The Mission Accessible Near-Earth Objects Survey (MANOS): First Photometric Results
    The Mission Accessible Near-Earth Objects Survey aims to physically characterize sub-km near-Earth objects (NEOs). We report the first photometric results from the survey that began in 2013 August. Photometric observations were performed using 1-4 m class telescopes around the world. We present rotational periods and light curve amplitudes for 86 sub-km NEOs, though in some cases only lower limits are provided. Our main goal is to obtain light curves for small NEOs (typically, sub-km objects) and estimate their rotational periods, light curve amplitudes, and shapes. These properties are used for a statistical study to constrain overall properties of the NEO population. A weak correlation seems to indicate that smaller objects are more spherical than larger ones. We also report seven NEOs that are fully characterized (light curve and visible spectra) as the most suitable candidates for a future human or robotic mission. Viable mission targets are objects fully characterized, with v NHATS 12 km s-1, and a rotational period P > 1 hr. Assuming a similar rate of object characterization as reported in this paper, approximately 1230 NEOs need to be characterized in order to find 100 viable mission targets.
  2. Bannister, M., Alexandersen, M., Benecchi, S., Chen, Y., Delsanti, A., Fraser, W., Gladman, B., Granvik, M., Grundy, W., Guilbert-Lepoutre, A., Gwyn, S., Ip, W., Jakubik, M., Jones, R., Kaib, N., Kavelaars, J., Lacerda, P., Lawler, S., Lehner, M., Lin, H., Lykawka, P., Marsset, M., Murray-Clay, R., Noll, K., Parker, A., Petit, J., Pike, R., Rousselot, P., Schwamb, M., Shankman, C., Veres, P., Vernazza, P., Volk, K., Wang, S., Weryk, R., 2016, AJ, 152, 212, OSSOS. IV. Discovery of a Dwarf Planet Candidate in the 9:2 Resonance with Neptune
    We report the discovery and orbit of a new dwarf planet candidate, 2015 RR245, by the Outer Solar System Origins Survey (OSSOS). The orbit of 2015 RR245 is eccentric (e = 0.586), with a semimajor axis near 82 au, yielding a perihelion distance of 34 au. 2015 RR245 has g-r=0.59+/- 0.11 and absolute magnitude {H}r=3.6+/- 0.1; for an assumed albedo of p V = 12%, the object has a diameter of 670 km. Based on astrometric measurements from OSSOS and Pan-STARRS1, we find that 2015 RR245 is securely trapped on ten-megayear timescales in the 9:2 mean-motion resonance with Neptune. It is the first trans-Neptunian object (TNO) identified in this resonance. On hundred-megayear timescales, particles in 2015 RR245-like orbits depart and sometimes return to the resonance, indicating that 2015 RR245 likely forms part of the long-lived metastable population of distant TNOs that drift between resonance sticking and actively scattering via gravitational encounters with Neptune. The discovery of a 9:2 TNO stresses the role of resonances in the long-term evolution of objects in the scattering disk and reinforces the view that distant resonances are heavily populated in the current solar system. This object further motivates detailed modeling of the transient sticking population.
  3. Herrmann, K., Hunter, D., Zhang, H., Elmegreen, B., 2016, AJ, 152, 177, Mass-to-light versus Color Relations for Dwarf Irregular Galaxies
    We have determined new relations between UBV colors and mass-to-light ratios (M/L) for dwarf irregular (dIrr) galaxies, as well as for transformed g - r. These M/L to color relations (MLCRs) are based on stellar mass density profiles determined for 34 LITTLE THINGS dwarfs from spectral energy distribution fitting to multi-wavelength surface photometry in passbands from the FUV to the NIR. These relations can be used to determine stellar masses in dIrr galaxies for situations where other determinations of stellar mass are not possible. Our MLCRs are shallower than comparable MLCRs in the literature determined for spiral galaxies. We divided our dwarf data into four metallicity bins and found indications of a steepening of the MLCR with increased oxygen abundance, perhaps due to more line blanketing occurring at higher metallicity.
  4. Nimmo, F., Hamilton, D., McKinnon, W., Schenk, P., Binzel, R., Bierson, C., Beyer, R., Moore, J., Stern, S., Weaver, H., Olkin, C., Young, L., Smith, K., Moore, J., McKinnon, W., Spencer, J., Beyer, R., Binzel, R., Buie, M., Buratti, B., Cheng, A., Cruikshank, D., Ore, C., Earle, A., Gladstone, R., Grundy, W., Howard, A., Lauer, T., Linscott, I., Nimmo, F., Parker, J., Porter, S., Reitsema, H., Reuter, D., Roberts, J., Robbins, S., Schenk, P., Showalter, M., Singer, K., Strobel, D., Summers, M., Tyler, L., White, O., Umurhan, O., Banks, M., Barnouin, O., Bray, V., Carcich, B., Chaikin, A., Chavez, C., Conrad, C., Hamilton, D., Howett, C., Hofgartner, J., Kammer, J., Lisse, C., Marcotte, A., Parker, A., Retherford, K., Saina, M., Runyon, K., Schindhelm, R., Stansberry, J., Steffl, A., Stryk, T., Throop, H., Tsang, C., Verbiscer, A., Winters, H., Zangari, A., Stern, S., Weaver, H., Olkin, C., Young, L., Smith, K., 2016, Natur, 540, 94, Reorientation of Sputnik Planitia implies a subsurface ocean on Pluto
    The deep nitrogen-covered basin on Pluto, informally named Sputnik Planitia, is located very close to the longitude of Plutos tidal axis and may be an impact feature, by analogy with other large basins in the Solar System. Reorientation of Sputnik Planitia arising from tidal and rotational torques can explain the basins present-day location, but requires the feature to be a positive gravity anomaly, despite its negative topography. Here we argue that if Sputnik Planitia did indeed form as a result of an impact and if Pluto possesses a subsurface ocean, the required positive gravity anomaly would naturally result because of shell thinning and ocean uplift, followed by later modest nitrogen deposition. Without a subsurface ocean, a positive gravity anomaly requires an implausibly thick nitrogen layer (exceeding 40 kilometres). To prolong the lifetime of such a subsurface ocean to the present day and to maintain ocean uplift, a rigid, conductive water-ice shell is required. Because nitrogen deposition is latitude-dependent, nitrogen loading and reorientation may have exhibited complex feedbacks.
  5. Hamilton, D., Stern, S., Moore, J., Young, L., Binzel, R., Buie, M., Buratti, B., Cheng, A., Ennico, K., Grundy, W., Linscott, I., McKinnon, W., Olkin, C., Reitsema, H., Reuter, D., Schenk, P., Showalter, M., Spencer, J., Tyler, G., Weaver, H., 2016, Natur, 540, 97, The rapid formation of Sputnik Planitia early in Pluto's history
    Pluto's Sputnik Planitia is a bright, roughly circular feature that resembles a polar ice cap. It is approximately 1,000 kilometres across and is centred on a latitude of 25 degrees north and a longitude of 175 degrees, almost directly opposite the side of Pluto that always faces Charon as a result of tidal locking. One explanation for its location includes the formation of a basin in a giant impact, with subsequent upwelling of a dense interior ocean. Once the basin was established, ice would naturally have accumulated there. Then, provided that the basin was a positive gravity anomaly (with or without the ocean), true polar wander could have moved the feature towards the Pluto-Charon tidal axis, on the far side of Pluto from Charon. Here we report modelling that shows that ice quickly accumulates on Pluto near latitudes of 30 degrees north and south, even in the absence of a basin, because, averaged over its orbital period, those are Pluto's coldest regions. Within a million years of Charon's formation, ice deposits on Pluto concentrate into a single cap centred near a latitude of 30 degrees, owing to the runaway albedo effect. This accumulation of ice causes a positive gravity signature that locks, as Pluto's rotation slows, to a longitude directly opposite Charon. Once locked, Charon raises a permanent tidal bulge on Pluto, which greatly enhances the gravity signature of the ice cap. Meanwhile, the weight of the ice in Sputnik Planitia causes the crust under it to slump, creating its own basin (as has happened on Earth in Greenland). Even if the feature is now a modest negative gravity anomaly, it remains locked in place because of the permanent tidal bulge raised by Charon. Any movement of the feature away from 30 degrees latitude is countered by the preferential recondensation of ices near the coldest extremities of the cap. Therefore, our modelling suggests that Sputnik Planitia formed shortly after Charon did and has been stable, albeit gradually losing volume, over the age of the Solar System.
  6. Reddy, V., Sanchez, J., Bottke, W., Thirouin, A., Rivera-Valentin, E., Kelley, M., Ryan, W., Cloutis, E., Tegler, S., Ryan, E., Taylor, P., Richardson, J., Moskovitz, N., Le Corre, L., 2016, AJ, 152, 162, Physical Characterization of 2 M Diameter Near-Earth Asteroid 2015 TC25: A Possible Boulder from E-type Asteroid (44) Nysa
    Small near-Earth asteroids (NEAs) (<20 m) are interesting, because they are progenitors for meteorites in our terrestrial collection. The physical characteristics of these small NEAs are crucial to our understanding of the effectiveness of our atmosphere in filtering low-strength impactors. In the past, the characterization of small NEAs has been a challenge, because of the difficulty in detecting them prior to close Earth flyby. In this study, we physically characterized the 2 m diameter NEA 2015 TC25 using ground-based optical, near-infrared and radar assets during a close flyby of the Earth (distance 128,000 km) in 2015 October 12. Our observations suggest that its surface composition is similar to aubrites, a rare class of high-albedo differentiated meteorites. Aubrites make up only 0.14% of all known meteorites in our terrestrial meteorite collection. 2015 TC25 is also a very fast rotator with a period of 133 6 s. We combined the spectral and dynamical properties of 2015 TC25 and found the best candidate source body in the inner main belt to be the 70 km diameter E-type asteroid (44) Nysa. We attribute the difference in spectral slope between the two objects to the lack of regolith on the surface of 2015 TC25. Using the albedo of E-type asteroids (50%-60%) we refine the diameter of 2015 TC25 to 2 m, making it one of the smallest NEAs ever to be characterized.
  7. Jao, W., Nelan, E., Henry, T., Franz, O., Wasserman, L., 2016, AJ, 152, 153, Cool Subdwarf Investigations. III. Dynamical Masses of Low-metallicity Subdwarfs
    We report dynamical mass measurements for the components of the previously known double-lined spectroscopic subdwarfs G 006-026 B and C using the Fine Guidance Sensors on the Hubble Space Telescope. To build the empirical mass-luminosity relation for low-metallicity subdwarfs, we collect four other subdwarf systems with dynamical masses that we compare to theoretical models for various metallicities on the mass-luminosity relation. For most stars, they fall in the regions where the models predict them to be low metallicity. This effort highlights the scarcity of dynamical masses for subdwarfs, and that much work remains to be done to improve the mass errors and metallicity measurements of low-mass subdwarfs in our Galaxy.
  8. Benedetti-Rossi, G., Sicardy, B., Buie, M., Ortiz, J., Vieira-Martins, R., Keller, J., Braga-Ribas, F., Camargo, J., Assafin, M., Morales, N., Duffard, R., Dias-Oliveira, A., Santos-Sanz, P., Desmars, J., Gomes-Junior, A., Leiva, R., Bardecker, J., Bean, J., Olsen, A., Ruby, D., Sumner, R., Thirouin, A., Gomez-Munoz, M., Gutierrez, L., Wasserman, L., Charbonneau, D., Irwin, J., Levine, S., Skiff, B., 2016, AJ, 152, 156, Results from the 2014 November 15th Multi-chord Stellar Occultation by the TNO (229762) 2007 UK126
    We present results derived from the first multi-chord stellar occultation by the trans-Neptunian object (229762) 2007 UK126, observed on 2014 November 15. The event was observed by the Research and Education Collaborative Occultation Network project and International Occultation Timing Association collaborators throughout the United States. Use of two different data analysis methods obtain a satisfactory fit to seven chords, yielding an elliptical fit to the chords with an equatorial radius of R={338}-10+15 km and equivalent radius of {R}{eq}={319}-7+14 km. A circular fit also gives a radius of R={324}-23+30 km. Assuming that the object is a Maclaurin spheroid with indeterminate aspect angle, and using two published absolute magnitudes for the body, we derive possible ranges for geometric albedo between {p}V={0.159}-0.013+0.007 and {p}R={0.189}-0.015+0.009, and for the body oblateness between ={0.105}-0.040+0.050 and ={0.118}-0.048+0.055. For a nominal rotational period of 11.05 hr, an upper limit for density of = 1740 kg m-3 is estimated for the body.
  9. Williamson, K., Jorstad, S., Marscher, A., Larionov, V., Agudo, I., Arkharov, A., Blinov, D., Casadio, C., Gomez, J., Hagen-Thorn, V., Joshi, M., Konstantinova, T., Kopatskaya, E., Larionova, E., Larionova, L., Malmrose, M., McHardy, I., Molina, S., Morozova, D., Taylor, B., Troitsky, I., 2016, Galax, 4, 64, Correlation Analysis of Delays between Variations of Gamma-Ray and Optical Light Curves of Blazars
    We have been performing multi-wavelength monitoring of a sample of -ray blazars since the launch of the Fermi Gamma-ray Space Telescope in 2008. We present -ray and optical light curves for several quasars and BL Lac objects from the sample to illustrate different patterns of variability. We investigate correlations between -ray and R-band light curves and, if these are statistically significant, determine delays between variations at the two wavebands. Such time delays can reveal the relative locations of the emitting regions in AGN jets and the origin of the high-energy photons. We present preliminary results of this analysis. Of the 29 blazars with sufficient time coverage, 17 display a significant, singular, correlated time lag when tested over the entire 7-year period. Of these sources, the six that exhibit a consistent time lag across a majority of epochs of high activity have lags of 0 7 days; the 11 without consistency across epochs of high activity generally display longer mean lags, with -ray leading optical. Eleven sources display no significant singular correlation over either the entire 7-year period or across shorter intervals. No significant difference is apparent between the BL Lac objects and FSRQs. Even after 7 years of monitoring, our correlation analysis remains plagued with uncertainties due to insufficient data.
  10. Hutter, D., Zavala, R., Tycner, C., Benson, J., Hummel, C., Sanborn, J., Franz, O., Johnston, K., 2016, ApJS, 227, 4, Surveying the Bright Stars by Optical Interferometry. I. A Search for Multiplicity among Stars of Spectral Types F-K
    We present the first results from an ongoing survey for multiplicity among the bright stars using the Navy Precision Optical Interferometer (NPOI). We first present a summary of NPOI observations of known multiple systems, including the first detection of the companion of Scuti with precise relative astrometry, to illustrate the instruments detection sensitivity for binaries at magnitude differences m 3 over the range of angular separation 3-860 milliarcseconds (mas). A limiting m700 3.5 is likely for binaries where the component spectral types differ by less than two. Model fits to these data show good agreement with published orbits, and we additionally present a new orbit solution for one of these stars, Her. We then discuss early results of the survey of bright stars at slant -20. This survey, which complements previous surveys of the bright stars using speckle interferometry, initially emphasizes bright stars of spectral types F0 through K2. We report observations of 41 stars of apparent visual magnitude mV slant 4.30, all having been observed on multiple nights. Analysis of these data produces fitted angular separations, position angles, and component magnitude differences for six previously known visual binaries. Three additional systems were examined as possible binaries, but no conclusive detection could be made. No evidence of close stellar companions within our detection limit of m 3 was found for the remaining 32 stars observed; however, uniform-disk angular diameters are reported for 11 of the resolved stars in this last group.
  11. Cibulkova, H., Durech, J., Vokrouhlicky, D., Kaasalainen, M., Oszkiewicz, D., 2016, A&A, 596, A57, Distribution of spin-axes longitudes and shape elongations of main-belt asteroids
    Context. Large all-sky surveys provide us with a lot of photometric data that are sparse in time (typically a few measurements per night) and can be potentially used for the determination of shapes and rotational states of asteroids. The method generally used to derive these parameters is the light curve inversion. However, for most asteroids their sparse data are not accurate enough to derive a unique model and the light curve inversion method is thus not very efficient.
    Aims: To fully utilize photometry sparse in time, we developed a new simplified model and applied it on the data from the Lowell photometric database. Our aim was to derive spin axis orientations and shape elongations of asteroids and to find out if there are some differences in distributions of these parameters for selected subpopulations.
    Methods: We modeled asteroids as geometrically scattering triaxial ellipsoids. Observed values of mean brightness and the dispersion of brightness were compared with computed values obtained from the parameters of the model, I.e., the ecliptical longitude and latitude of the pole and the ratios a/b, b/c of axes of the ellipsoid. These parameters were optimized to get the best agreement with the observation.
    Results: We found that the distribution of for main-belt asteroids is not uniform and is dependent on the inclination of the orbit. Surprisingly, the nonuniformity of distribution is larger for asteroids residing on low-inclination orbits. We also studied distributions of a/b for several groups of asteroids and found that small asteroids (D< 25 km) are on average more elongated than large ones.
  12. Grundy, W., Cruikshank, D., Gladstone, G., Howett, C., Lauer, T., Spencer, J., Summers, M., Buie, M., Earle, A., Ennico, K., Parker, J., Porter, S., Singer, K., Stern, S., Verbiscer, A., Beyer, R., Binzel, R., Buratti, B., Cook, J., Dalle Ore, C., Olin, C., Parker, A., Protopapa, S., Quirico, E., Retherford, K., Robbins, S., Schmitt, B., Stansberry, J., Umurhan, O., Weaver, H., Young, L., Zangari, A., Bray, V., Cheng, A., McKinnon, W., McNutt, R., Morre, J., Nimmo, F., Reuter, D., Schenk, P., New Horizons Science Team, Stern, S., Bagenal, F., Ennico, K., Gladstone, G., Grundy, W., McKinnon, W., Moore, J., Olkin, C., Spencer, J., Weaver, H., Young, L., Andert, T., Barnouin, O., Beyer, R., Binzel, R., Bird, M., Bray, V., Brozovic, M., Buie, M., Buratti, B., Cheng, A., Cook, J., Cruikshank, D., Dalle Ore, C., Earler, A., Elliott, H., Greathouse, T., Hahn, M., Hamilton, D., Hill, M., Hinson, D., Hofgartner, J., Horanyi, M., Howard, A., Howett, C., Jennings, D., Kammer, J., Kollmann, P., Lauer, T., Lavvas, P., Linscott, I., Lunsford, A., McComas, D., McNutt, R., Mutchler, M., Nimmo, F., Nunez, J., Paetzold, M., Parker, A., Parker, J., Philippe, S., Piquette, M., Porter, S., Protopapa, S., Quirico, E., Reitsema, H., Reuter, D., Robbins, S., Roberts, J., Runyon, K., Schenk, P., Schindhelm, R., Schmitt, B., Showalter, M., Singer, K., Stansberry, J., Steffl, A., Strobel, D., Stryk, T., Summers, M., Szalay, J., Throop, H., Tsang, C., Tyler, G., Umurhan, O., Verbiscer, A., Versteeg, M., Weigle, G., White, O., Woods, W., Young, E., Zangari, A., 2016, Natur, 539, 65, The formation of Charon's red poles from seasonally cold-trapped volatiles
    A unique feature of Pluto's large satellite Charon is its dark red northern polar cap. Similar colours on Pluto's surface have been attributed to tholin-like organic macromolecules produced by energetic radiation processing of hydrocarbons. The polar location on Charon implicates the temperature extremes that result from Charon's high obliquity and long seasons in the production of this material. The escape of Pluto's atmosphere provides a potential feedstock for a complex chemistry. Gas from Pluto that is transiently cold-trapped and processed at Charon's winter pole was proposed as an explanation for the dark coloration on the basis of an image of Charon's northern hemisphere, but not modelled quantitatively. Here we report images of the southern hemisphere illuminated by Pluto-shine and also images taken during the approach phase that show the northern polar cap over a range of longitudes. We model the surface thermal environment on Charon and the supply and temporary cold-trapping of material escaping from Pluto, as well as the photolytic processing of this material into more complex and less volatile molecules while cold-trapped. The model results are consistent with the proposed mechanism for producing the observed colour pattern on Charon.
  13. Maier, E., Chien, L., Hunter, D., 2016, AJ, 152, 134, Turbulence and Star Formation in a Sample of Spiral Galaxies
    We investigate turbulent gas motions in spiral galaxies and their importance to star formation in far outer disks, where the column density is typically far below the critical value for spontaneous gravitational collapse. Following the methods of Burkhart et al. on the Small Magellanic Cloud, we use the third and fourth statistical moments, as indicators of structures caused by turbulence, to examine the neutral hydrogen (H I) column density of a sample of spiral galaxies selected from The H I Nearby Galaxy Survey. We apply the statistical moments in three different methodsthe galaxy as a whole, divided into a function of radii and then into grids. We create individual grid maps of kurtosis for each galaxy. To investigate the relation between these moments and star formation, we compare these maps with their far-ultraviolet images taken by the Galaxy Evolution Explorer satellite.We find that the moments are largely uniform across the galaxies, in which the variation does not appear to trace any star-forming regions. This may, however, be due to the spatial resolution of our analysis, which could potentially limit the scale of turbulent motions that we are sensitive to greater than 700 pc. From comparison between the moments themselves, we find that the gas motions in our sampled galaxies are largely supersonic. This analysis also shows that the Burkhart et al. methods may be applied not just to dwarf galaxies but also to normal spiral galaxies.
  14. Benedict, G., Henry, T., Franz, O., McArthur, B., Wasserman, L., Jao, W., Cargile, P., Dieterich, S., Bradley, A., Nelan, E., Whipple, A., 2016, AJ, 152, 141, The Solar Neighborhood. XXXVII: The Mass-Luminosity Relation for Main-sequence M Dwarfs
    We present a mass-luminosity relation (MLR) for red dwarfs spanning a range of masses from 0.62 {{ M }} to the end of the stellar main sequence at 0.08 {{ M }} . The relation is based on 47 stars for which dynamical masses have been determined, primarily using astrometric data from Fine Guidance Sensors (FGS) 3 and 1r, white-light interferometers on the Hubble Space Telescope (HST), and radial velocity data from McDonald Observatory. For our HST/FGS sample of 15 binaries, component mass errors range from 0.4% to 4.0% with a median error of 1.8%. With these and masses from other sources, we construct a V-band MLR for the lower main sequence with 47 stars and a K-band MLR with 45 stars with fit residuals half of those of the V band. We use GJ 831 AB as an example, obtaining an absolute trigonometric parallax, abs = 125.3 0.3 mas, with orbital elements yielding {{ M }}{{A}}=0.270+/- 0.004 {{ M }} and {{ M }}{{B}}=0.145+/- 0.002 {{ M }} . The mass precision rivals that derived for eclipsing binaries. A remaining major task is the interpretation of the intrinsic cosmic scatter in the observed MLR for low-mass stars in terms of physical effects. In the meantime, useful mass values can be estimated from the MLR for the ubiquitous red dwarfs that account for 75% of all stars, with applications ranging from the characterization of exoplanet host stars to the contribution of red dwarfs to the mass of the universe.

    Based on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555.

  15. Fulton, B., Howard, A., Weiss, L., Sinukoff, E., Petigura, E., Isaacson, H., Hirsch, L., Marcy, G., Henry, G., Grunblatt, S., Huber, D., von Braun, K., Boyajian, T., Kane, S., Wittrock, J., Horch, E., Ciardi, D., Howell, S., Wright, J., Ford, E., 2016, ApJ, 830, 46, Three Temperate Neptunes Orbiting Nearby Stars
    We present the discovery of three modestly irradiated, roughly Neptune-mass planets orbiting three nearby Solar-type stars. HD 42618 b has a minimum mass of 15.4 2.4 {M}\oplus , a semimajor axis of 0.55 au, an equilibrium temperature of 337 K, and is the first planet discovered to orbit the solar analogue host star, HD 42618. We also discover new planets orbiting the known exoplanet host stars HD 164922 and HD 143761 ( CrB). The new planet orbiting HD 164922 has a minimum mass of 12.9 1.6 {M}\oplus and orbits interior to the previously known Jovian mass planet orbiting at 2.1 au. HD 164922 c has a semimajor axis of 0.34 au and an equilibrium temperature of 418 K. HD 143761 c orbits with a semimajor axis of 0.44 au, has a minimum mass of 25 2 {M}\oplus , and is the warmest of the three new planets with an equilibrium temperature of 445 K. It orbits exterior to the previously known warm Jupiter in the system. A transit search using space-based CoRoT data and ground-based photometry from the Automated Photometric Telescopes (APTs) at Fairborn Observatory failed to detect any transits, but the precise, high-cadence APT photometry helped to disentangle planetary-reflex motion from stellar activity. These planets were discovered as part of an ongoing radial velocity survey of bright, nearby, chromospherically inactive stars using the Automated Planet Finder (APF) telescope at Lick Observatory. The high-cadence APF data combined with nearly two decades of radial velocity data from Keck Observatory and gives unprecedented sensitivity to both short-period low-mass, and long-period intermediate-mass planets.

    Based on observations obtained at the W. M. Keck Observatory, which is operated jointly by the University of California and the California Institute of Technology. Keck time was granted for this project by the University of HawaiI, the University of California, and NASA.

  16. Barros, S., Brown, D., Hebrard, G., Gomez Maqueo Chew, Y., Anderson, D., Boumis, P., Delrez, L., Hay, K., Lam, K., Llama, J., Lendl, M., McCormac, J., Skiff, B., Smalley, B., Turner, O., Vanhuysse, M., Armstrong, D., Boisse, I., Bouchy, F., Collier Cameron, A., Faedi, F., Gillon, M., Hellier, C., Jehin, E., Liakos, A., Meaburn, J., Osborn, H., Pepe, F., Plauchu-Frayn, I., Pollacco, D., Queloz, D., Rey, J., Spake, J., Segransan, D., Triaud, A., Udry, S., Walker, S., Watson, C., West, R., Wheatley, P., 2016, A&A, 593, A113, WASP-113b and WASP-114b, two inflated hot Jupiters with contrasting densities

    Aims: We present the discovery and characterisation of the exoplanets WASP-113b and WASP-114b by the WASP surveys, SOPHIE and CORALIE.
    Methods: The planetary nature of the systems was established by performing follow-up photometric and spectroscopic observations. The follow-up data were combined with the WASP-photometry and analysed with an MCMC code to obtain system parameters.
    Results: The host stars WASP-113 and WASP-114 are very similar. They are both early G-type stars with an effective temperature of ~5900 K, [Fe/H] ~ 0.12, and log g~ 4.1 dex. However, WASP-113 is older than WASP-114. Although the planetary companions have similar radii, WASP-114b is almost four times heavier than WASP-113b. WASP-113b has a mass of 0.48 MJup and an orbital period of ~4.5 days; WASP-114b has a mass of 1.77 MJup and an orbital period of ~1.5 days. Both planets have inflated radii, in particular WASP-113 with a radius anomaly of = 0.35. The high scale height of WASP-113b (~950 km) makes it a good target for follow-up atmospheric observations.
  17. Boro Saikia, S., Jeffers, S., Morin, J., Petit, P., Folsom, C., Marsden, S., Donati, J., Cameron, R., Hall, J., Perdelwitz, V., Reiners, A., Vidotto, A., 2016, A&A, 594, A29, A solar-like magnetic cycle on the mature K-dwarf 61 Cygni A (HD 201091)
    Context. The long-term monitoring of magnetic cycles in cool stars is a key diagnostic in understanding how dynamo generation and amplification of magnetic fields occur in stars similar in structure to the Sun.
    Aims: We investigated the temporal evolution of a possible magnetic cycle of 61 Cyg A. The magnetic cycle is determined from 61 Cyg A's large-scale field over its activity cycle using spectropolarimetric observations and compared to the solar large-scale magnetic field.
    Methods: We used the tomographic technique of Zeeman Doppler imaging (ZDI) to reconstruct the large-scale magnetic geometry of 61 Cyg A over multiple observational epochs spread over a time span of nine years. We investigated the time evolution of the different components of the large-scale field and compared it with the evolution of the star's chromospheric activity by measuring the flux in three different chromospheric indicators: Ca II H&K, H and Ca II infrared triplet lines. We also compared our results with the star's coronal activity using XMM-Newton observations.
    Results: The large-scale magnetic geometry of 61 Cyg A exhibits polarity reversals in both poloidal and toroidal field components, in phase with its chromospheric activity cycle. We also detect weak solar-like differential rotation with a shear level similar to that of the Sun. During our observational time span of nine years, 61 Cyg A exhibits solar- like variations in its large-scale field geometry as it evolves from minimum activity to maximum activity and vice versa. During its activity minimum in epoch 2007.59, ZDI reconstructs a simple dipolar geometry which becomes more complex when it approaches activity maximum in epoch 2010.55. The radial field flips polarity and reverts back to a simple geometry in epoch 2013.61. The field is strongly dipolar and the evolution of the dipole component of the field is reminiscent of solar behaviour. The polarity reversal of the large-scale field indicates a magnetic cycle that is in phase with the chromospheric and coronal cycle.
  18. Johns-Krull, C., Prato, L., McLane, J., Ciardi, D., van Eyken, J., Chen, W., Stauffer, J., Beichman, C., Frazier, S., Boden, A., Morales-Calderon, M., Rebull, L., 2016, ApJ, 830, 15, H Variability in PTFO8-8695 and the Possible Direct Detection of Emission from a 2 Million Year Old Evaporating Hot Jupiter
    We use high time cadence, high spectral resolution optical observations to detect excess H emission from the 2-3 Myr old weak-lined T Tauri star PTFO 8-8695. This excess emission appears to move in velocity as expected if it were produced by the suspected planetary companion to this young star. The excess emission is not always present, but when it is, the predicted velocity motion is often observed. We have considered the possibility that the observed excess emission is produced by stellar activity (flares), accretion from a disk, or a planetary companion; we find the planetary companion to be the most likely explanation. If this is the case, the strength of the H line indicates that the emission comes from an extended volume around the planet, likely fed by mass loss from the planet which is expected to be overflowing its Roche lobe.
  19. Schleicher, D., knight, M., 2016, AJ, 152, 89, The Extremely Low Activity Comet 209P/LINEAR During Its Extraordinary Close Approach in 2014
    We present results from our observing campaign of Comet 209P/LINEAR during its exceptionally close approach to Earth during 2014 May, the third smallest perigee of any comet in two centuries. These circumstances permitted us to pursue several studies of this intrinsically faint object, including measurements of gas and dust production rates, searching for coma morphology, and direct detection of the nucleus to measure its properties. Indeed, we successfully measured the lowest water production rates of an intact comet in over 35 years and a corresponding smallest active area, 0.007 km2. When combined with the nucleus size found from radar, this also yields the smallest active fraction for any comet, 0.024%. In all, this strongly suggests that 209P/LINEAR is on its way to becoming an inert object. The nucleus was detected but could not easily be disentangled from the inner coma due to seeing variations and changing spatial scales. Even so, we were able to measure a double-peaked lightcurve consistent with the shorter of two viable rotational periods found by Hergenrother. Radial profiles of the dust coma are quite steep, similar to that observed for some other very anemic comets, and suggest that vaporizing icy grains are present.
  20. Gao, P., Plavchan, P., Gagne, J., Furlan, E., Bottom, M., Anglada-Escude, G., White, R., Davison, C., Beichman, C., Brinkworth, C., Johnson, J., Ciardi, D., Wallace, K., Mennesson, B., von Braun, K., Vasisht, G., Prato, L., Kane, S., Tanner, A., Crawford, T., Latham, D., Rougeot, R., Geneser, C., Catanzarite, J., 2016, PASP, 128, 104501, Retrieval of Precise Radial Velocities from Near-infrared High-resolution Spectra of Low-mass Stars
    Given that low-mass stars have intrinsically low luminosities at optical wavelengths and a propensity for stellar activity, it is advantageous for radial velocity (RV) surveys of these objects to use near-infrared (NIR) wavelengths. In this work, we describe and test a novel RV extraction pipeline dedicated to retrieving RVs from low-mass stars using NIR spectra taken by the CSHELL spectrograph at the NASA Infrared Telescope Facility, where a methane isotopologue gas cell is used for wavelength calibration. The pipeline minimizes the residuals between the observations and a spectral model composed of templates for the target star, the gas cell, and atmospheric telluric absorption; models of the line-spread function, continuum curvature, and sinusoidal fringing; and a parameterization of the wavelength solution. The stellar template is derived iteratively from the science observations themselves without a need for separate observations dedicated to retrieving it. Despite limitations from CSHELLs narrow wavelength range and instrumental systematics, we are able to (1) obtain an RV precision of 35 m s-1 for the RV standard star GJ 15 A over a time baseline of 817 days, reaching the photon noise limit for our attained signal-to-noise ratio; (2) achieve 3 m s-1 RV precision for the M giant SV Peg over a baseline of several days and confirm its long-term RV trend due to stellar pulsations, as well as obtain nightly noise floors of 2-6 m s-1 and (3) show that our data are consistent with the known masses, periods, and orbital eccentricities of the two most massive planets orbiting GJ 876. Future applications of our pipeline to RV surveys using the next generation of NIR spectrographs, such as iSHELL, will enable the potential detection of super-Earths and mini-Neptunes in the habitable zones of M dwarfs.
  21. Bannister, M., Kavelaars, J., Petit, J., Gladman, B., Gwyn, S., Chen, Y., Volk, K., Alexandersen, M., Benecchi, S., Delsanti, A., Fraser, W., Granvik, M., Grundy, W., Guilbert-Lepoutre, A., Hestroffer, D., Ip, W., Jakubik, M., Jones, R., Kaib, N., Kavelaars, C., Lacerda, P., Lawler, S., Lehner, M., Lin, H., Lister, T., Lykawka, P., Monty, S., Marsset, M., Murray-Clay, R., Noll, K., Parker, A., Pike, R., Rousselot, P., Rusk, D., Schwamb, M., Shankman, C., Sicardy, B., Vernazza, P., Wang, S., 2016, AJ, 152, 70, The Outer Solar System Origins Survey. I. Design and First-quarter Discoveries
    We report the discovery, tracking, and detection circumstances for 85 trans-Neptunian objects (TNOs) from the first 42 deg2 of the Outer Solar System Origins Survey. This ongoing r-band solar system survey uses the 0.9 deg2 field of view MegaPrime camera on the 3.6 m Canada-France-Hawaii Telescope. Our orbital elements for these TNOs are precise to a fractional semimajor axis uncertainty <0.1%. We achieve this precision in just two oppositions, as compared to the normal three to five oppositions, via a dense observing cadence and innovative astrometric technique. These discoveries are free of ephemeris bias, a first for large trans-Neptunian surveys. We also provide the necessary information to enable models of TNO orbital distributions to be tested against our TNO sample. We confirm the existence of a cold kernel of objects within the main cold classical Kuiper Belt and infer the existence of an extension of the stirred cold classical Kuiper Belt to at least several au beyond the 2:1 mean motion resonance with Neptune. We find that the population model of Petit et al. remains a plausible representation of the Kuiper Belt. The full survey, to be completed in 2017, will provide an exquisitely characterized sample of important resonant TNO populations, ideal for testing models of giant planet migration during the early history of the solar system.
  22. Egeland, R., Soon, W., Baliunas, S., Hall, J., Pevtsov, A., Henry, G., 2016, csss, 6, Dynamo Sensitivity In Solar Analogs With 50 Years Of Ca II H & K Activity
    The Sun has a steady 11-year cycle in magnetic activity most well-known by the rising and falling in the occurrence of dark sunspots on the solar disk in visible bandpasses. The 11-year cycle is also manifest in the variations of emission in the Ca II H & K line cores, due to non-thermal (i.e. magnetic) heating in the lower chromosphere. The large variation in Ca II H & K emission allows for study of the patterns of long-term variability in other stars thanks to synoptic monitoring with the Mount Wilson Observatory HK photometers (1966-2003) and Lowell Observatory Solar-Stellar Spectrograph (1994-present). Overlapping measurements for a set of 27 nearby solar-analog (spectral types G0-G5) stars were used to calibrate the two instruments and construct time series of magnetic activity up to 50 years in length. Precise properties of fundamental importance to the dynamo are available from Hipparcos, the Geneva-Copenhagen Survey, and CHARA interferometry. Using these long time series and measurements of fundamental properties, we do a comparative study of stellar "twins" to explore the sensitivity of the stellar dynamo to small changes to structure, rotation, and composition. We also compare this sample to the Sun and find hints that the regular periodic variability of the solar cycle may be rare among its nearest neighbors in parameter space.
  23. Massey, P., Neugent, K., Smart, B., 2016, AJ, 152, 62, A Spectroscopic Survey of Massive Stars in M31 and M33
    We describe our spectroscopic follow-up to the Local Group Galaxy Survey (LGGS) photometry of M31 and M33. We have obtained new spectroscopy of 1895 stars, allowing us to classify 1496 of them for the first time. Our study has identified many foreground stars, and established membership for hundreds of early- and mid-type supergiants. We have also found nine new candidate luminous blue variables and a previously unrecognized Wolf-Rayet star. We republish the LGGS M31 and M33 catalogs with improved coordinates, and including spectroscopy from the literature and our new results. The spectroscopy in this paper is responsible for the vast majority of the stellar classifications in these two nearby spiral neighbors. The most luminous (and hence massive) of the stars in our sample are early-type B supergiants, as expected; the more massive O stars are more rare and fainter visually, and thus mostly remain unobserved so far. The majority of the unevolved stars in our sample are in the 20-40 M range.

    The spectroscopic observations reported here were obtained at the MMT Observatory, a joint facility of the University of Arizona and the Smithsonian Institution. MMT telescope time was granted by NOAO, through the Telescope System Instrumentation Program (TSIP). TSIP is funded by the National Science Foundation. This paper uses data products produced by the OIR Telescope Data Center, supported by the Smithsonian Astrophysical Observatory.

  24. Baines, E., Dollinger, M., Guenther, E., Hatzes, A., Hrudkovu, M., van Belle, G., 2016, AJ, 152, 66, Spectroscopic and Interferometric Measurements of Nine K Giant Stars
    We present spectroscopic and interferometric measurements for a sample of nine K giant stars. These targets are of particular interest because they are slated for stellar oscillation observations. Our improved parameters will directly translate into reduced errors in the final masses for these stars when interferometric radii and asteroseismic densities are combined. Here, we determine each stars limb-darkened angular diameter, physical radius, luminosity, bolometric flux, effective temperature, surface gravity, metallicity, and mass. When we compare our interferometric and spectroscopic results, we find no systematic offsets in the diameters and the values generally agree within the errors. Our interferometric temperatures for seven of the nine stars are hotter than those determined from spectroscopy with an average difference of about 380 K.
  25. Armstrong, J., Baines, E., Schmitt, H., Restaino, S., Clark, J., Benson, J., Hutter, D., Zavala, R., van Belle, G., 2016, SPIE, 9907, 990702, The Navy Precision Optical Interferometer: an update
    We describe the current status of the Navy Precision Optical Interferometer (NPOI), including developments since the last SPIE meeting. The NPOI group has added stations as far as 250m from the array center and added numerous infrastructure improvements. Science programs include stellar diameters and limb darkening, binary orbits, Be star disks, exoplanet host stars, and progress toward high-resolution stellar surface imaging. Technical and infrastructure projects include on-sky demonstrations of baseline bootstrapping with six array elements and of the VISION beam combiner, control system updates, integration of the long delay lines, and updated firmware for the Classic beam combiner. Our plans to add up to four 1.8 m telescopes are no longer viable, but we have recently acquired separate funding for adding three 1 m AO-equipped telescopes and an infrared beam combiner to the array.
  26. Matter, A., Lopez, B., Antonelli, P., Lehmitz, M., Bettonvil, F., Beckmann, U., Lagarde, S., Jaffe, W., Petrov, R., Berio, P., Millour, F., Robbe-Dubois, S., Glindemann, A., Bristow, P., Schoeller, M., Lanz, T., Henning, T., Weigelt, G., Heininger, M., Morel, S., Cruzalebes, P., Meisenheimer, K., Hofferbert, R., Wolf, S., Bresson, Y., Agocs, T., Allouche, F., Augereau, J., Avila, G., Bailet, C., Behrend, J., van Belle, G., Berger, J., van Boekel, R., Bourget, P., Brast, R., Clausse, J., Connot, C., Conzelmann, R., Csepany, G., Danchi, W., Delbo, M., Dominik, C., van Duin, A., Elswijk, E., Fantei, Y., Finger, G., Gabasch, A., Gonte, F., Graser, U., Guitton, F., Guniat, S., De Haan, M., Haguenauer, P., Hanenburg, H., Hofmann, K., Hogerheijde, M., ter Horst, R., Hron, J., Hummel, C., Isderda, J., Ives, D., Jakob, G., Jasko, A., Jolley, P., Kiraly, S., Kragt, J., Kroener, T., Kroes, G., Kuindersma, S., Labadie, L., Laun, W., Leinert, C., Lizon, J., Lucuix, C., Marcotto, A., Martinache, F., Martinot-Lagarde, G., Mauclert, N., Mehrgan, L., Meilland, A., Mellein, M., Menardi, S., Merand, A., Neumann, U., Nussbaum, E., Ottogalli, S., Palsa, R., Panduro, J., Pantin, E., Percheron, I., Phan Duc, T., Pott, J., Pozna, E., Roelfsema, R., Rupprecht, G., Schertl, D., Schmidt, C., Schuil, M., Spang, A., Stegmeier, J., Tromp, N., Vakili, F., Vannier, M., Wagner, K., Venema, L., Woillez, J., 2016, SPIE, 9907, 99070A, An overview of the mid-infrared spectro-interferometer MATISSE: science, concept, and current status
    MATISSE is the second-generation mid-infrared spectrograph and imager for the Very Large Telescope Interferometer (VLTI) at Paranal. This new interferometric instrument will allow significant advances by opening new avenues in various fundamental research fields: studying the planet-forming region of disks around young stellar objects, understanding the surface structures and mass loss phenomena affecting evolved stars, and probing the environments of black holes in active galactic nuclei. As a first breakthrough, MATISSE will enlarge the spectral domain of current optical interferometers by offering the L and M bands in addition to the N band. This will open a wide wavelength domain, ranging from 2.8 to 13 m, exploring angular scales as small as 3 mas (L band) / 10 mas (N band). As a second breakthrough, MATISSE will allow mid-infrared imaging - closure-phase aperture-synthesis imaging - with up to four Unit Telescopes (UT) or Auxiliary Telescopes (AT) of the VLTI. Moreover, MATISSE will offer a spectral resolution range from R 30 to R 5000. Here, we present one of the main science objectives, the study of protoplanetary disks, that has driven the instrument design and motivated several VLTI upgrades (GRA4MAT and NAOMI). We introduce the physical concept of MATISSE including a description of the signal on the detectors and an evaluation of the expected performances. We also discuss the current status of the MATISSE instrument, which is entering its testing phase, and the foreseen schedule for the next two years that will lead to the first light at Paranal.
  27. Kraus, S., Monnier, J., Ireland, M., Duchene, G., Espaillat, C., Honig, S., Juhasz, A., Mordasini, C., Olofsson, J., Paladini, C., Stassun, K., Turner, N., Vasisht, G., Harries, T., Bate, M., Gonzalez, J., Matter, A., Zhu, Z., Panic, O., Regaly, Z., Morbidelli, A., Meru, F., Wolf, S., Ilee, J., Berger, J., Zhao, M., Kral, Q., Morlok, A., Bonsor, A., Ciardi, D., Kane, S., Kratter, K., Laughlin, G., Pepper, J., Raymond, S., Labadie, L., Nelson, R., Weigelt, G., ten Brummelaar, T., Pierens, A., Oudmaijer, R., Kley, W., Pope, B., Jensen, E., Bayo, A., Smith, M., Boyajian, T., Quiroga-Nunez, L., Millan-Gabet, R., Chiavassa, A., Gallenne, A., Reynolds, M., de Wit, W., Wittkowski, M., Millour, F., Gandhi, P., Ramos Almeida, C., Alonso Herrero, A., Packham, C., Kishimoto, M., Tristram, K., Pott, J., Surdej, J., Buscher, D., Haniff, C., Lacour, S., Petrov, R., Ridgway, S., Tuthill, P., van Belle, G., Armitage, P., Baruteau, C., Benisty, M., Bitsch, B., Paardekooper, S., Pinte, C., Masset, F., Rosotti, G., 2016, SPIE, 9907, 99071K, Planet Formation Imager (PFI): science vision and key requirements
    The Planet Formation Imager (PFI) project aims to provide a strong scientific vision for ground-based optical astronomy beyond the upcoming generation of Extremely Large Telescopes. We make the case that a breakthrough in angular resolution imaging capabilities is required in order to unravel the processes involved in planet formation. PFI will be optimised to provide a complete census of the protoplanet population at all stellocentric radii and over the age range from 0.1 to 100 Myr. Within this age period, planetary systems undergo dramatic changes and the final architecture of planetary systems is determined. Our goal is to study the planetary birth on the natural spatial scale where the material is assembled, which is the "Hill Sphere" of the forming planet, and to characterise the protoplanetary cores by measuring their masses and physical properties. Our science working group has investigated the observational characteristics of these young protoplanets as well as the migration mechanisms that might alter the system architecture. We simulated the imprints that the planets leave in the disk and study how PFI could revolutionise areas ranging from exoplanet to extragalactic science. In this contribution we outline the key science drivers of PFI and discuss the requirements that will guide the technology choices, the site selection, and potential science/technology tradeoffs.
  28. Ireland, M., Monnier, J., Kraus, S., Isella, A., Minardi, S., Petrov, R., ten Brummelaar, T., Young, J., Vasisht, G., Mozurkewich, D., Rinehart, S., Michael, E., van Belle, G., Woillez, J., 2016, SPIE, 9907, 99071L, Status of the Planet Formation Imager (PFI) concept
    The Planet Formation Imager (PFI) project aims to image the period of planet assembly directly, resolving structures as small as a giant planet's Hill sphere. These images will be required in order to determine the key mechanisms for planet formation at the time when processes of grain growth, protoplanet assembly, magnetic fields, disk/planet dynamical interactions and complex radiative transfer all interact - making some planetary systems habitable and others inhospitable. We will present the overall vision for the PFI concept, focusing on the key technologies and requirements that are needed to achieve the science goals. Based on these key requirements, we will define a cost envelope range for the design and highlight where the largest uncertainties lie at this conceptual stage.
  29. Schmitt, H., Armstrong, J., Restaino, S., van Belle, G., 2016, SPIE, 9907, 99071X, Monitoring a decade of seeing at the NPOI site with quad cell measurements
    As a part of regular operations, the Navy Precision Optical Interferometer (NPOI) uses Narrow Angle Trackers (NAT) for atmospheric tip-tilt correction. This correction is done using a quad cell array for each station, and is based on the error signals measured by these arrays. We compiled NPOI NAT jitter information for the period of 2005 to 2014. Here we investigate the correlation of the NAT jitter between different NPOI stations, and determine a correction for shot-noise induced jitter. We present initial results from the correlation between NAT jitter and quasi simultaneous seeing measurements done with the Lowell Observatory 31" telescope, separated by 500 m. We also discuss some limitations of this technique and future improvements.
  30. Jorgensen, A., Schmitt, H., Armstrong, J., Baines, E., Hindsley, R., Mozurkewich, D., van Belle, G., 2016, SPIE, 9907, 990725, The new classic instrument for the navy precision optical interferometer
    The New Classic instrument was built as a electronics and computer upgrade to the existing Classic beam combiner at the Navy Precision Optical Interferometer (NPOI). The classic beam combiner is able to record 32 of 96 available channels and has a data throughput limitation which results in a low duty cycle. Additionally the computing power of the Classic system limited the amount of fringe tracking that was possible. The New Classic system implements a high-throughput data acquisition system which is capable of recording all 96 channels continuously. It also has a modern high-speed computer for data management and data processing. The computer is sufficiently powerful to implement more sophisticated fringe-tracking algorithms than the Classic system, including multi-baseline bootstrapping. In this paper we described the New Classic hardware and software, including the fringe-tracking algorithm, performance, and the user interface. We also show some initial results from the first 5-station, 4-baseline bootstrapping carried out in January 2015.
  31. Jorgensen, A., Mozurkewich, D., Armstrong, J., Schmitt, H., Baines, E., van Belle, G., 2016, SPIE, 9907, 99072C, Multi-baseline chain bootstrapping with new classic at the NPOI
    Imaging with optical interferometers requires fringe measurements on baseline long enough to resolve the target. These long baselines typically have low fringe contrast. Phasing them requires fringe tracking on shorter baselines which typically have greater fringe contrast and combining the fringe-tracking signals on the short baselines to phase the long baselines in a baseline bootstrapping configuration. On long resolving baselines coherent integration also becomes necessary in order to shorten the integration time. This paper addresses both the baseline bootstrapping and the coherent integration. The Navy Precision Optical Interferometer (NPOI) is laid out in a way which permits long-baseline phasing from shorter baselines in a multi-baseline scheme. The New Classic instrument for NPOI was designed specifically to implement the multi-baseline bootstrapping capability and multi-baseline observations can now be carried out routinely at the NPOI. This paper provides details about the bootstrapping scheme at NPOI and shows some initial results. We also discuss the bootstrapping error budget, describe our new Bayesian coherent integration algorithm and compare its performance to theory.
  32. Levine, S., DeGroff, W., 2016, SPIE, 9906, 990621, Status and imaging performance of Lowell Observatory's Discovery Channel Telescope in its first year of full science operations
    Lowell Observatory's Discovery Channel Telescope (DCT) is a 4.3-m telescope designed and constructed for optical and near infrared astronomical observation. The DCT is equipped with a cube capable of carrying five instruments along with the wave front sensing and guider systems at the f/6.1 RC focus. The facility formally finished commissioning at the end of 2014. In 2015 the DCT ran in full science operations mode. This report recaps recent progress on the operations and instrument fronts, and then concentrates on the delivered image quality as measured with science imaging data. The system is delivering image quality at or better than the system top level requirements for open loop operations. Corrected to the zenith, the median seeing in the science images from 2015 was 0."93; first quartile seeing was 0.0074. The open loop site contribution to the seeing is roughly 0."40, which is better than the requirements of < 0."47. The FWHM degrades with wind speed at the rate of roughly 0."10/(m/s), and the seeing degrades more with wind speed when the wind is from the East.
  33. Sokal, K., Johnson, K., Indebetouw, R., Massey, P., 2016, ApJ, 826, 194, The Prevalence and Impact of Wolf-Rayet Stars in Emerging Massive Star Clusters
    We investigate Wolf-Rayet (WR) stars as a source of feedback contributing to the removal of natal material in the early evolution of massive star clusters. Despite previous work suggesting that massive star clusters clear out their natal material before the massive stars evolve into the WR phase, WR stars have been detected in several emerging massive star clusters. These detections suggest that the timescale for clusters to emerge can be at least as long as the time required to produce WR stars (a few million years), and could also indicate that WR stars may be providing the tipping point in the combined feedback processes that drive a massive star cluster to emerge. We explore the potential overlap between the emerging phase and the WR phase with an observational survey to search for WR stars in emerging massive star clusters hosting WR stars. We select candidate emerging massive star clusters from known radio continuum sources with thermal emission and obtain optical spectra with the 4 m Mayall Telescope at Kitt Peak National Observatory and the 6.5 m MMT.4 We identify 21 sources with significantly detected WR signatures, which we term emerging WR clusters. WR features are detected in 50% of the radio-selected sample, and thus we find that WR stars are commonly present in currently emerging massive star clusters. The observed extinctions and ages suggest that clusters without WR detections remain embedded for longer periods of time, and may indicate that WR stars can aid, and therefore accelerate, the emergence process.
  34. Johns-Krull, C., McLane, J., Prato, L., Crockett, C., Jaffe, D., Hartigan, P., Beichman, C., Mahmud, N., Chen, W., Skiff, B., Cauley, P., Jones, J., Mace, G., 2016, ApJ, 826, 206, A Candidate Young Massive Planet in Orbit around the Classical T Tauri Star CI Tau
    The 2 Myr old classical T Tauri star CI Tau shows periodic variability in its radial velocity (RV) variations measured at infrared (IR) and optical wavelengths. We find that these observations are consistent with a massive planet in a 9 day period orbit. These results are based on 71 IR RV measurements of this system obtained over five years, and on 26 optical RV measurements obtained over nine years. CI Tau was also observed photometrically in the optical on 34 nights over one month in 2012. The optical RV data alone are inadequate to identify an orbital period, likely the result of star spot and activity-induced noise for this relatively small data set. The infrared RV measurements reveal significant periodicity at 9 days. In addition, the full set of optical and IR RV measurements taken together phase coherently and with equal amplitudes to the 9 day period. Periodic RV signals can in principle be produced by cool spots, hotspots, and reflection of the stellar spectrum off the inner disk, in addition to resulting from a planetary companion. We have considered each of these and find the planet hypothesis most consistent with the data. The RV amplitude yields an M\sin I of 8.1 M Jup; in conjunction with a 1.3 mm continuum emission measurement of the circumstellar disk inclination from the literature, we find a planet mass of 11.3 M Jup, assuming alignment of the planetary orbit with the disk.

    This paper includes data taken at The McDonald Observatory of The University of Texas at Austin.

  35. Massey, P., Evans, K., 2016, ApJ, 826, 224, The Red Supergiant Content of M31*
    We investigate the red supergiant (RSG) population of M31, obtaining the radial velocities of 255 stars. These data substantiate membership of our photometrically selected sample, demonstrating that Galactic foreground stars and extragalactic RSGs can be distinguished on the basis of B - V, V - R two-color diagrams. In addition, we use these spectra to measure effective temperatures and assign spectral types, deriving physical properties for 192 RSGs. Comparison with the solar metallicity Geneva evolutionary tracks indicates astonishingly good agreement. The most luminous RSGs in M31 are likely evolved from 25-30 M stars, while the vast majority evolved from stars with initial masses of 20 M or less. There is an interesting bifurcation in the distribution of RSGs with effective temperatures that increases with higher luminosities, with one sequence consisting of early K-type supergiants, and with the other consisting of M-type supergiants that become later (cooler) with increasing luminosities. This separation is only partially reflected in the evolutionary tracks, although that might be due to the mis-match in metallicities between the solar Geneva models and the higher-than-solar metallicity of M31. As the luminosities increase the median spectral type also increases; I.e., the higher mass RSGs spend more time at cooler temperatures than do those of lower luminosities, a result which is new to this study. Finally we discuss what would be needed observationally to successfully build a luminosity function that could be used to constrain the mass-loss rates of RSGs as our Geneva colleagues have suggested.

    Observations reported here were obtained at the MMT Observatory, a joint facility of the University of Arizona and the Smithsonian Institution. This paper uses data products produced by the OIR Telescope Data Center, supported by the Smithsonian Astrophysical Observatory.

  36. Gopalan, G., Plavchan, P., van Eyken, J., Ciardi, D., von Braun, K., Kane, S., 2016, PASP, 128, 084504, Application of the Trend Filtering Algorithm for Photometric Time Series Data
    Detecting transient light curves (e.g., transiting planets) requires high-precision data, and thus it is important to effectively filter systematic trends affecting ground-based wide-field surveys. We apply an implementation of the Trend Filtering Algorithm (TFA) to the 2MASS calibration catalog and select Palomar Transient Factory (PTF) photometric time series data. TFA is successful at reducing the overall dispersion of light curves, however, it may over-filter intrinsic variables and increase instantaneous dispersion when a template set is not judiciously chosen. In an attempt to rectify these issues we modify the original TFA from the literature by including measurement uncertainties in its computation, including ancillary data correlated with noise, and algorithmically selecting a template set using clustering algorithms as suggested by various authors. This approach may be particularly useful for appropriately accounting for variable photometric precision surveys and/or combined data sets. In summary, our contributions are to provide a MATLAB software implementation of TFA and a number of modifications tested on synthetics and real data, summarize the performance of TFA and various modifications on real ground-based data sets (2MASS and PTF), and assess the efficacy of TFA and modifications using synthetic light curve tests consisting of transiting and sinusoidal variables. While the transiting variables test indicates that these modifications confer no advantage to transit detection, the sinusoidal variables test indicates potential improvements in detection accuracy.
  37. Egeland, R., Soon, W., Baliunas, S., Hall, J., Pevtsov, A., Henry, G., 2016, csss, 72, The Solar Dynamo Zoo
    We present composite time series of Ca II H & K line core emission indices of up to 50 years in length for a set of 27 solar-analog stars (spectral types G0-G5; within 10% of the solar mass) and the Sun. These unique data are available thanks to the long-term dedicated efforts of the Mount Wilson Observatory HK project, the Lowell Observatory Solar-Stellar Spectrograph, and the National Solar Observatory/Air Force Research Laboratory/Sacramento Peak K-line monitoring program. The Ca II H & K emission originates in the lower chromosphere and is strongly correlated with the presence of magnetic plage regions in the Sun. These synoptic observations allow us to trace the patterns long-term magnetic variability and explore dynamo behavior over a wide range of rotation regimes and stellar evolution timescales.In this poster, the Ca HK observations are expressed using the Mount Wilson S-index. Each time series is accompanied by a Lomb-Scargle periodogram, fundemental stellar parameters derived from the Geneva-Copenhagen Survey, and statistics derived from the time series including the median S-index value and seasonal and long-term amplitudes. Statistically significant periodogram peaks are ranked according to a new cycle quality metric. We find that clear, simple, Sun-like cycles are the minority in this sample.
  38. Ricker, G., Vanderspek, R., Winn, J., Seager, S., Berta-Thompson, Z., Levine, A., Villasenor, J., Latham, D., Charbonneau, D., Holman, M., Johnson, J., Sasselov, D., Szentgyorgyi, A., Torres, G., Bakos, G., Brown, T., Christensen-Dalsgaard, J., Kjeldsen, H., Clampin, M., Rinehart, S., Deming, D., Doty, J., Dunham, E., Ida, S., Kawai, N., Sato, B., Jenkins, J., Lissauer, J., Jernigan, G., Kaltenegger, L., Laughlin, G., Lin, D., McCullough, P., Narita, N., Pepper, J., Stassun, K., Udry, S., 2016, SPIE, 9904, 99042B, The Transiting Exoplanet Survey Satellite
    No abstract found.
  39. Kiehlmann, S., Savolainen, T., Jorstad, S., Sokolovsky, K., Schinzel, F., Marscher, A., Larionov, V., Agudo, I., Akitaya, H., Benitez, E., Berdyugin, A., Blinov, D., Bochkarev, N., Borman, G., Burenkov, A., Casadio, C., Doroshenko, V., Efimova, N., Fukazawa, Y., Gomez, J., Grishina, T., Hagen-Thorn, V., Heidt, J., Hiriart, D., Itoh, R., Joshi, M., Kawabata, K., Kimeridze, G., Kopatskaya, E., Korobtsev, I., Krajci, T., Kurtanidze, O., Kurtanidze, S., Larionova, E., Larionova, L., Lindfors, E., Lopez, J., McHardy, I., Molina, S., Moritani, Y., Morozova, D., Nazarov, S., Nikolashvili, M., Nilsson, K., Pulatova, N., Reinthal, R., Sadun, A., Sasada, M., Savchenko, S., Sergeev, S., Sigua, L., Smith, P., Sorcia, M., Spiridonova, O., Takaki, K., Takalo, L., Taylor, B., Troitsky, I., Uemura, M., Ugolkova, L., Ui, T., Yoshida, M., Zensus, J., Zhdanova, V., 2016, A&A, 592, C1, Polarization angle swings in blazars: The case of 3C 279 (Corrigendum)
    No abstract found.
  40. Parker, A., Buie, M., Grundy, W., Noll, K., 2016, ApJL, 825, L9, Discovery of a Makemakean Moon
    We describe the discovery of a satellite in orbit about the dwarf planet (136472) Makemake. This satellite, provisionally designated S/2015 (136472) 1, was detected in imaging data collected with the Hubble Space Telescopes Wide Field Camera 3 on UTC 2015 April 27 at 7.80 0.04 mag fainter than Makemake and at a separation of 0.57. It likely evaded detection in previous satellite searches due to a nearly edge-on orbital configuration, placing it deep within the glare of Makemake during a substantial fraction of its orbital period. This configuration would place Makemake and its satellite near a mutual event season. Insufficient orbital motion was detected to make a detailed characterization of its orbital properties, prohibiting a measurement of the system mass with the discovery data alone. Preliminary analysis indicates that if the orbit is circular, its orbital period must be longer than 12.4 days and must have a semimajor axis 21,000 km. We find that the properties of Makemakes moon suggest that the majority of the dark material detected in the system by thermal observations may not reside on the surface of Makemake, but may instead be attributable to S/2015 (136472) 1 having a uniform dark surface. This dark moon hypothesis can be directly tested with future James Webb Space Telescope observations. We discuss the implications of this discovery for the spin state, figure, and thermal properties of Makemake and the apparent ubiquity of trans-Neptunian dwarf planet satellites.
  41. van Belle, G., Creech-Eakman, M., Ruiz-Velasco, A., 2016, AJ, 152, 16, Bolometric Flux Estimation for Cool Evolved Stars
    Estimation of bolometric fluxes ({F}{{BOL}}) is an essential component of stellar effective temperature determination with optical and near-infrared interferometry. Reliable estimation of {F}{{BOL}} simply from broadband K-band photometry data is a useful tool in those cases were contemporaneous and/or wide-range photometry is unavailable for a detailed spectral energy distribution (SED) fit, as was demonstrated in Dyck et al. Recalibrating the intrinsic {F}{{BOL}} versus observed {F}{{2.2} {{m}}} relationship of that study with modern SED fitting routines, which incorporate the significantly non-blackbody, empirical spectral templates of the INGS spectral library (an update of the library in Pickles) and estimation of reddening, serves to greatly improve the accuracy and observational utility of this relationship. We find that {F}{{BOL}} values predicted are roughly 11% less than the corresponding values predicted in Dyck et al., indicating the effects of SED absorption features across bolometric flux curves.
  42. Michel, P., Cheng, A., Kuppers, M., Pravec, P., Blum, J., Delbo, M., Green, S., Rosenblatt, P., Tsiganis, K., Vincent, J., Biele, J., Ciarletti, V., Herique, A., Ulamec, S., Carnelli, I., Galvez, A., Benner, L., Naidu, S., Barnouin, O., Richardson, D., Rivkin, A., Scheirich, P., Moskovitz, N., Thirouin, A., Schwartz, S., Campo Bagatin, A., Yu, Y., 2016, AdSpR, 57, 2529, Science case for the Asteroid Impact Mission (AIM): A component of the Asteroid Impact & Deflection Assessment (AIDA) mission
    The Asteroid Impact & Deflection Assessment (AIDA) mission is a joint cooperation between European and US space agencies that consists of two separate and independent spacecraft that will be launched to a binary asteroid system, the near-Earth asteroid Didymos, to test the kinetic impactor technique to deflect an asteroid. The European Asteroid Impact Mission (AIM) is set to rendezvous with the asteroid system to fully characterize the smaller of the two binary components a few months prior to the impact by the US Double Asteroid Redirection Test (DART) spacecraft. AIM is a unique mission as it will be the first time that a spacecraft will investigate the surface, subsurface, and internal properties of a small binary near-Earth asteroid. In addition it will perform various important technology demonstrations that can serve other space missions.

    The knowledge obtained by this mission will have great implications for our understanding of the history of the Solar System. Having direct information on the surface and internal properties of small asteroids will allow us to understand how the various processes they undergo work and transform these small bodies as well as, for this particular case, how a binary system forms. Making these measurements from up close and comparing them with ground-based data from telescopes will also allow us to calibrate remote observations and improve our data interpretation of other systems. With DART, thanks to the characterization of the target by AIM, the mission will be the first fully documented impact experiment at asteroid scale, which will include the characterization of the target's properties and the outcome of the impact. AIDA will thus offer a great opportunity to test and refine our understanding and models at the actual scale of an asteroid, and to check whether the current extrapolations of material strength from laboratory-scale targets to the scale of AIDA's target are valid. Moreover, it will offer a first check of the validity of the kinetic impactor concept to deflect a small body and lead to improved efficiency for future kinetic impactor designs.

    This paper focuses on the science return of AIM, the current knowledge of its target from ground-based observations, and the instrumentation planned to get the necessary data.

  43. Hunter, D., Elmegreen, B., Gehret, E., 2016, AJ, 151, 136, Young Star Clusters in the Outer Disks of LITTLE THINGS Dwarf Irregular Galaxies
    We examine FUV images of the LITTLE THINGS sample of nearby dwarf irregular (dIrr) and Blue Compact Dwarf galaxies to identify distinct young regions in their far outer disks. We use these data, obtained with the Galaxy Evolution Explorer satellite, to determine the furthest radius at which in situ star formation can currently be identified. The FUV knots are found at distances from the center of the galaxies of 1-8 disk scale lengths and have ages of slant 20 Myr and masses of 20 M{} to 1 105M{} . The presence of young clusters and OB associations in the outer disks of dwarf galaxies shows that dIrrs do have star formation taking place there in spite of the extreme nature of the environment. Most regions are found where the H I surface density is 1 M{} pc-2, though both the H I and dispersed old stars go out much further. This limiting density suggests a cutoff in the ability to form distinct OB associations and perhaps even stars. We compare the star formation rates in the FUV regions to the average rates expected at their radii and beyond from the observed gas, using the conventional correlation for gas-rich regions. The localized rates are typically 10% of the expected average rates for the outer disks. Either star formation in dIrrs at surface densities < 1 {M} pc-2 occurs without forming distinct associations, or the Kennicutt-Schmidt relation over-predicts the rate beyond this point. In the latter case, the stellar disks in the far-outer parts of dIrrs result from scattering of stars from the inner disk.
  44. Ruiz Velasco, A., van Belle, G., Creech-Eakman, M., 2016, csss, 52, Time-Dependent Diameters Of Mira Variable Stars
    We examined archival data of the Palomar Testbed Inteferometer (PTI) covering a sample of 85 Mira variable stars. The sample contains the three most common types: 65 oxygen-rich (M-type), 11 carbon-rich (C-type) and 9 of the intermediary S-type; Periods range from 150 to 600 days. The PTI database spans over nine years of data; up to 80 epochs for individual stars, spanning multiple pulsation cycles per star. These interferometric angular sizes, along with ancillary measures of distance and bolometric flux, can be used to determine linear size and effective temperature, respectively. Additionally, the PTI data can be divided into narrowband data across the K-band (2.0-2.4 m), allowing separate analysis of spatially resolved continuum and prominent molecular-bandhead regions of these stars, which typically pulsate out of phase.In this posterwe presentpreliminary results that show average sizes changes of 40% for the stellar radii and 44 % for the molecular envelopes.
  45. Hanley, J., Thompson, G., Roe, H., Grundy, W., 2016, tac, 27, Poster 15: Exploring the Composition of Titan's Lakes through Laboratory Experiments
    Previous studies have shown that the lakes of Titan are composed of methane and/or ethane, but the relative proportions are mostly unclear. Understanding the past and current stability of these lakes requires characterizing the interactions of liquid methane and ethane. Mixtures of these hydrocarbons are not fully understood, and a phase diagram has not yet been established. Our current cryogenic laboratory setup reaches temperatures down to 30 K, allowing us to map the full liquidus line (freezing points) of the methane-ethane system as a function of composition and temperature. While pure methane and ethane both freeze around 91 K, our results show that when mixed, the freezing point is depressed down to 72 K for a mixture of 64% methane and 36% ethane. Any mixing of these two species together will depress the freezing point of the lake below Titan's surface temperature, preventing them from freezing. Also, when ethane ice forms, it freezes on the bottom of the liquid, while methane ice freezes at the top of the liquid, implying ethane ice is denser than the solution, while methane ice is less dense; this holds for all concentrations. Concurrently with the phase diagram determination, we have acquired transmission spectra of these mixtures to understand how the spectral features change with concentration and temperature. These results will help interpret future observational data, and guide current theoretical models.
  46. Krick, J., Ingalls, J., Carey, S., von Braun, K., Kane, S., Ciardi, D., Plavchan, P., Wong, I., Lowrance, P., 2016, ApJ, 824, 27, Spitzer IRAC Sparsely Sampled Phase Curve of the Exoplanet Wasp-14B
    Motivated by a high Spitzer IRAC oversubscription rate, we present a new technique of randomly and sparsely sampling the phase curves of hot Jupiters. Snapshot phase curves are enabled by technical advances in precision pointing as well as careful characterization of a portion of the central pixel on the array. This method allows for observations which are a factor of approximately two more efficient than full phase curve observations, and are furthermore easier to insert into the Spitzer observing schedule. We present our pilot study from this program using the exoplanet WASP-14b. Data of this system were taken both as a sparsely sampled phase curve as well as a staring-mode phase curve. Both data sets, as well as snapshot-style observations of a calibration star, are used to validate this technique. By fitting our WASP-14b phase snapshot data set, we successfully recover physical parameters for the transit and eclipse depths as well as the amplitude and maximum and minimum of the phase curve shape of this slightly eccentric hot Jupiter. We place a limit on the potential phase to phase variation of these parameters since our data are taken over many phases over the course of a year. We see no evidence for eclipse depth variations compared to other published WASP-14b eclipse depths over a 3.5 year baseline.
  47. Herrmann, K., Hunter, D., Elmegreen, B., 2016, AJ, 151, 145, Surface Brightness Profiles of Dwarf Galaxies. II. Color Trends and Mass Profiles
    In this second paper of a series, we explore the B - V, U - B, and FUV-NUV radial color trends from a multi-wavelength sample of 141 dwarf disk galaxies. Like spirals, dwarf galaxies have three types of radial surface brightness profiles: (I) single exponential throughout the observed extent (the minority), (II) down-bending (the majority), and (III) up-bending. We find that the colors of (1) Type I dwarfs generally become redder with increasing radius, unlike spirals which have a blueing trend that flattens beyond 1.5 disk scale lengths, (2) Type II dwarfs come in six different flavors, one of which mimics the U shape of spirals, and (3) Type III dwarfs have a stretched S shape where the central colors are flattish, become steeply redder toward the surface brightness break, then remain roughly constant beyond, which is similar to spiral Type III color profiles, but without the central outward bluing. Faint (-9 > MB > -14) Type II dwarfs tend to have continuously red or U shaped colors and steeper color slopes than bright (-14 > MB > -19) Type II dwarfs, which additionally have colors that become bluer or remain constant with increasing radius. Sm dwarfs and BCDs tend to have at least some blue and red radial color trend, respectively. Additionally, we determine stellar surface mass density () profiles and use them to show that the break in generally remains in Type II dwarfs (unlike Type II spirals) but generally disappears in Type III dwarfs (unlike Type III spirals). Moreover, the break in is strong, intermediate, and weak in faint dwarfs, bright dwarfs, and spirals, respectively, indicating that may straighten with increasing galaxy mass. Finally, the average stellar surface mass density at the surface brightness break is roughly 1-2 M pc-2 for Type II dwarfs but higher at 5.9 M pc-2 or 27 M pc-2 for Type III BCDs and dIms, respectively.
  48. Thirouin, A., Sheppard, S., Noll, K., Moskovitz, N., Ortiz, J., Doressoundiram, A., 2016, AJ, 151, 148, Rotational Properties of the Haumea Family Members and Candidates: Short-term Variability.
    Haumea is one of the most interesting and intriguing trans-Neptunian objects (TNOs). It is a large, bright, fast rotator, and its spectrum indicates nearly pure water ice on the surface. It has at least two satellites and a dynamically related family of more than 10 TNOs with very similar proper orbital parameters and similar surface properties. The Haumean family is the only one currently known in the trans-Neptunian belt. Various models have been proposed, but the formation of the family remains poorly understood. In this work, we have investigated the rotational properties of the family members and unconfirmed family candidates with short-term variability studies, and report the most complete review to date. We present results based on five years of observations and report the short-term variability of five family members and seven candidates. The mean rotational periods, from Maxwellian fits to the frequency distributions, are 6.27 1.19 hr for the confirmed family members, 6.44 1.16 hr for the candidates, and 7.65 0.54 hr for other TNOs (without relation to the family). According to our study, there is a possibility that Haumea family members rotate faster than other TNOs; however, the sample of family members is still too limited for a secure conclusion. We also highlight the fast rotation of 2002 GH32. This object has a 0.36 0.02 mag amplitude lightcurve and a rotational period of about 3.98 hr. Assuming 2002 GH32 is a triaxial object in hydrostatic equilibrium, we derive a lower limit to the density of 2.56 g cm-3. This density is similar to Haumeas and much more dense than other small TNO densities.
  49. Fischer, D., Anglada-Escude, G., Arriagada, P., Baluev, R., Bean, J., Bouchy, F., Buchhave, L., Carroll, T., Chakraborty, A., Crepp, J., Dawson, R., Diddams, S., Dumusque, X., Eastman, J., Endl, M., Figueira, P., Ford, E., Foreman-Mackey, D., Fournier, P., Furesz, G., Gaudi, B., Gregory, P., Grundahl, F., Hatzes, A., Hebrard, G., Herrero, E., Hogg, D., Howard, A., Johnson, J., Jorden, P., Jurgenson, C., Latham, D., Laughlin, G., Loredo, T., Lovis, C., Mahadevan, S., McCracken, T., Pepe, F., Perez, M., Phillips, D., Plavchan, P., Prato, L., Quirrenbach, A., Reiners, A., Robertson, P., Santos, N., Sawyer, D., Segransan, D., Sozzetti, A., Steinmetz, T., Szentgyorgyi, A., Udry, S., Valenti, J., Wang, S., Wittenmyer, R., Wright, J., 2016, PASP, 128, 066001, State of the Field: Extreme Precision Radial Velocities
    The Second Workshop on Extreme Precision Radial Velocities defined circa 2015 the state of the art Doppler precision and identified the critical path challenges for reaching 10 cm s-1 measurement precision. The presentations and discussion of key issues for instrumentation and data analysis and the workshop recommendations for achieving this bold precision are summarized here. Beginning with the High Accuracy Radial Velocity Planet Searcher spectrograph, technological advances for precision radial velocity (RV) measurements have focused on building extremely stable instruments. To reach still higher precision, future spectrometers will need to improve upon the state of the art, producing even higher fidelity spectra. This should be possible with improved environmental control, greater stability in the illumination of the spectrometer optics, better detectors, more precise wavelength calibration, and broader bandwidth spectra. Key data analysis challenges for the precision RV community include distinguishing center of mass (COM) Keplerian motion from photospheric velocities (time correlated noise) and the proper treatment of telluric contamination. Success here is coupled to the instrument design, but also requires the implementation of robust statistical and modeling techniques. COM velocities produce Doppler shifts that affect every line identically, while photospheric velocities produce line profile asymmetries with wavelength and temporal dependencies that are different from Keplerian signals. Exoplanets are an important subfield of astronomy and there has been an impressive rate of discovery over the past two decades. However, higher precision RV measurements are required to serve as a discovery technique for potentially habitable worlds, to confirm and characterize detections from transit missions, and to provide mass measurements for other space-based missions. The future of exoplanet science has very different trajectories depending on the precision that can ultimately be achieved with Doppler measurements.
  50. Gagne, J., Plavchan, P., Gao, P., Anglada-Escude, G., Furlan, E., Davison, C., Tanner, A., Henry, T., Riedel, A., Brinkworth, C., Latham, D., Bottom, M., White, R., Mills, S., Beichman, C., Johnson, J., Ciardi, D., Wallace, K., Mennesson, B., von Braun, K., Vasisht, G., Prato, L., Kane, S., Mamajek, E., Walp, B., Crawford, T., Rougeot, R., Geneser, C., Catanzarite, J., 2016, ApJ, 822, 40, A High-precision Near-infrared Survey for Radial Velocity Variable Low-mass Stars Using CSHELL and a Methane Gas Cell
    We present the results of a precise near-infrared (NIR) radial velocity (RV) survey of 32 low-mass stars with spectral types K2-M4 using CSHELL at the NASA InfraRed Telescope Facility in the K band with an isotopologue methane gas cell to achieve wavelength calibration and a novel, iterative RV extraction method. We surveyed 14 members of young (25-150 Myr) moving groups, the young field star Eridani, and 18 nearby (<25 pc) low-mass stars and achieved typical single-measurement precisions of 8-15 m s-1with a long-term stability of 15-50 m s-1 over longer baselines. We obtain the best NIR RV constraints to date on 27 targets in our sample, 19 of which were never followed by high-precision RV surveys. Our results indicate that very active stars can display long-term RV variations as low as 25-50 m s-1 at 2.3125 m, thus constraining the effect of jitter at these wavelengths. We provide the first multiwavelength confirmation of GJ 876 bc and independently retrieve orbital parameters consistent with previous studies. We recovered RV variabilities for HD 160934 AB and GJ 725 AB that are consistent with their known binary orbits, and nine other targets are candidate RV variables with a statistical significance of 3-5. Our method, combined with the new iSHELL spectrograph, will yield long-term RV precisions of 5 m s-1 in the NIR, which will allow the detection of super-Earths near the habitable zone of mid-M dwarfs.
  51. Covey, K., Agueros, M., Law, N., Liu, J., Ahmadi, A., Laher, R., Levitan, D., Sesar, B., Surace, J., 2016, ApJ, 822, 81, Why Are Rapidly Rotating M Dwarfs in the Pleiades so (Infra)red? New Period Measurements Confirm Rotation-dependent Color Offsets From the Cluster Sequence
    Stellar rotation periods (P rot) measured in open clusters have proved to be extremely useful for studying stars angular momentum content and rotationally driven magnetic activity, which are both age- and mass-dependent processes. While P rot measurements have been obtained for hundreds of solar-mass members of the Pleiades, measurements exist for only a few low-mass (<0.5 M ) members of this key laboratory for stellar evolution theory. To fill this gap, we report P rot for 132 low-mass Pleiades members (including nearly 100 with M 0.45 M ), measured from photometric monitoring of the cluster conducted by the Palomar Transient Factory in late 2011 and early 2012. These periods extend the portrait of stellar rotation at 125 Myr to the lowest-mass stars and re-establish the Pleiades as a key benchmark for models of the transport and evolution of stellar angular momentum. Combining our new P rot with precise BVIJHK photometry reported by Stauffer et al. and Kamai et al., we investigate known anomalies in the photometric properties of K and M Pleiades members. We confirm the correlation detected by Kamai et al. between a star's P rot and position relative to the main sequence in the cluster's color-magnitude diagram. We find that rapid rotators have redder (V - K) colors than slower rotators at the same V, indicating that rapid and slow rotators have different binary frequencies and/or photospheric properties. We find no difference in the photometric amplitudes of rapid and slow rotators, indicating that asymmetries in the longitudinal distribution of starspots do not scale grossly with rotation rate.
  52. Ruiz-Velasco, A., Felli, D., Migenes, V., Wiggins, B., 2016, ApJ, 822, 101, VLBA Surveys of OH Masers in Star-forming Regions. I. Satellite Lines
    Using the Very Long Baseline Array we performed a high-resolution OH maser survey in Galactic star-forming regions (SFRs). We observed all the ground state spectral lines: the main lines at 1665 and 1667 MHz and the satellite lines at 1612 and 1720 MHz. Due to the exceptionality of finding satellite lines in SFRs, we will focus our discussion on those lines. In our sample of 41 OH maser sources, five (12%) showed the 1612 MHz line and ten (24%) showed the 1720 MHz line, with only one source showing both lines. We find that 1720 MHz emission is correlated with the presence of H II regions, suggesting that this emission could be used to diagnose or trace high-mass star formation. We include an analysis of the possible mechanisms that could be causing this correlation as well as assessing the possible relationships between lines in our sample. In particular, the presence of magnetic fields seems to play an important role as we found Zeeman splitting in four of our sources (W75 N, W3(OH), W51 and NGC 7538). Our results have implications for current understanding of the formation of high-mass stars as well as on the masing processes present in SFRs.
  53. Knight, M., Fitzsimmons, A., Kelley, M., Snodgrass, C., 2016, ApJL, 823, L6, Comet 322P/SOHO 1: An Asteroid with the Smallest Perihelion Distance?
    We observed comet 322P/SOHO 1 (P/1999 R1) from the ground and with the Spitzer Space Telescope when it was between 2.2 and 1.2 au from the Sun. These are the first observations of any Solar and Heliospheric Observatory (SOHO)-discovered periodic comet by a non-solar observatory and allow us to investigate its behavior under typical cometary circumstances. 322P appeared inactive in all images. Its light curve suggests a rotation period of 2.8 0.3 hr and has an amplitude 0.3 mag, implying a density of at least 1000 kg m-3, considerably higher than that of any known comet. It has average colors of {g}\prime -{r}\prime =0.52+/- 0.04 and {r}\prime -{I}\prime =0.03+/- 0.06. We converted these to Johnson colors and found that the V - R color is consistent with average cometary colors, but R - I is somewhat bluer; these colors are most similar to V- and Q-type asteroids. Modeling of the optical and IR photometry suggests it has a diameter of 150-320 m and a geometric albedo of 0.09-0.42, with diameter and albedo inversely related. Our upper limits to any undetected coma are still consistent with a sublimation lifetime shorter than the typical dynamical lifetimes for Jupiter-family comets. These results suggest that 322P may be of asteroidal origin and only active in the SOHO fields of view via processes different from the volatile-driven activity of traditional comets. If so, it has the smallest perihelion distance of any known asteroid.

    Based on observations collected at the European Organisation for Astronomical Research in the Southern Hemisphere under ESO programme 095.C-0853, with Lowell Observatorys Discovery Channel Telescope, and with Spitzer Space Telescope under program 11104.

  54. Garcia, E., Muterspaugh, M., van Belle, G., Monnier, J., Stassun, K., Ghasempour, A., Clark, J., Zavala, R., Benson, J., Hutter, D., Schmitt, H., Baines, E., Jorgensen, A., Strosahl, S., Sanborn, J., Zawicki, S., Sakosky, M., Swihart, S., 2016, PASP, 128, 055004, Vision: A Six-telescope Fiber-fed Visible Light Beam Combiner for the Navy Precision Optical Interferometer
    Visible-light long baseline interferometry holds the promise of advancing a number of important applications in fundamental astronomy, including the direct measurement of the angular diameters and oblateness of stars, and the direct measurement of the orbits of binary and multiple star systems. To advance, the field of visible-light interferometry requires development of instruments capable of combining light from 15 baselines (6 telescopes) simultaneously. The Visible Imaging System for Interferometric Observations at NPOI (VISION) is a new visible light beam combiner for the Navy Precision Optical Interferometer (NPOI) that uses single-mode fibers to coherently combine light from up to six telescopes simultaneously with an image-plane combination scheme. It features a photometric camera for calibrations and spatial filtering from single-mode fibers with two Andor Ixon electron multiplying CCDs. This paper presents the VISION system, results of laboratory tests, and results of commissioning on-sky observations. A new set of corrections have been determined for the power spectrum and bispectrum by taking into account non-Gaussian statistics and read noise present in electron-multipying CCDs to enable measurement of visibilities and closure phases in the VISION post-processing pipeline. The post-processing pipeline has been verified via new on-sky observations of the O-type supergiant binary Orionis A, obtaining a flux ratio of 2.18+/- 0.13 with a position angle of 223.9 1.0 and separation 40.6+/- 1.8 mas over 570-750 nm, in good agreement with expectations from the previously published orbit.
  55. Kiehlmann, S., Savolainen, T., Jorstad, S., Sokolovsky, K., Schinzel, F., Marscher, A., Larionov, V., Agudo, I., Akitaya, H., Benitez, E., Berdyugin, A., Blinov, D., Bochkarev, N., Borman, G., Burenkov, A., Casadio, C., Doroshenko, V., Efimova, N., Fukazawa, Y., Gomez, J., Grishina, T., Hagen-Thorn, V., Heidt, J., Hiriart, D., Itoh, R., Joshi, M., Kawabata, K., Kimeridze, G., Kopatskaya, E., Korobtsev, I., Krajci, T., Kurtanidze, O., Kurtanidze, S., Larionova, E., Larionova, L., Lindfors, E., Lopez, J., McHardy, I., Molina, S., Moritani, Y., Morozova, D., Nazarov, S., Nikolashvili, M., Nilsson, K., Pulatova, N., Reinthal, R., Sadun, A., Sasada, M., Savchenko, S., Sergeev, S., Sigua, L., Smith, P., Sorcia, M., Spiridonova, O., Takaki, K., Takalo, L., Taylor, B., Troitsky, I., Uemura, M., Ugolkova, L., Ui, T., Yoshida, M., Zensus, J., Zhdanova, V., 2016, A&A, 590, A10, Polarization angle swings in blazars: The case of 3C 279
    Context. Over the past few years, on several occasions, large, continuous rotations of the electric vector position angle (EVPA) of linearly polarized optical emission from blazars have been reported. These events are often coincident with high energy -ray flares and they have attracted considerable attention, since they could allow us to probe the magnetic field structure in the -ray emitting region of the jet. The flat-spectrum radio quasar 3C 279 is one of the most prominent examples showing this behaviour.
    Aims: Our goal is to study the observed EVPA rotations and to distinguish between a stochastic and a deterministic origin of the polarization variability.
    Methods: We have combined multiple data sets of R-band photometry and optical polarimetry measurements of 3C 279, yielding exceptionally well-sampled flux density and polarization curves that cover a period of 2008-2012. Several large EVPA rotations are identified in the data. We introduce a quantitative measure for the EVPA curve smoothness, which is then used to test a set of simple random walk polarization variability models against the data.
    Results: 3C 279 shows different polarization variation characteristics during an optical low-flux state and a flaring state. The polarization variation during the flaring state, especially the smooth ~360 rotation of the EVPA in mid-2011, is not consistent with the tested stochastic processes.
    Conclusions: We conclude that, during the two different optical flux states, two different processes govern polarization variation, which is possibly a stochastic process during the low-brightness state and a deterministic process during the flaring activity.

    The measured and processed optical polarization and R-band photometry data are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr ( or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/590/A10

  56. Snodgrass, C., Jehin, E., Manfroid, J., Opitom, C., Fitzsimmons, A., Tozzi, G., Faggi, S., Yang, B., Knight, M., Conn, B., Lister, T., Hainaut, O., Bramich, D., Lowry, S., Rozek, A., Tubiana, C., Guilbert-Lepoutre, A., 2016, A&A, 588, A80, Distant activity of 67P/Churyumov-Gerasimenko in 2014: Ground-based results during the Rosetta pre-landing phase
    Context. As the ESA Rosetta mission approached, orbited, and sent a lander to comet 67P/Churyumov-Gerasimenko in 2014, a large campaign of ground-based observations also followed the comet.
    Aims: We constrain the total activity level of the comet by photometry and spectroscopy to place Rosetta results in context and to understand the large-scale structure of the comet's coma pre-perihelion.
    Methods: We performed observations using a number of telescopes, but concentrate on results from the 8 m VLT and Gemini South telescopes in Chile. We use R-band imaging to measure the dust coma contribution to the comet's brightness and UV-visible spectroscopy to search for gas emissions, primarily using VLT/FORS. In addition we imaged the comet in near-infrared wavelengths (JHK) in late 2014 with Gemini-S/Flamingos-2.
    Results: We find that the comet was already active in early 2014 at heliocentric distances beyond 4 au. The evolution of the total activity (measured by dust) followed previous predictions. No gas emissions were detected despite sensitive searches.
    Conclusions: The comet maintains a similar level of activity from orbit to orbit, and is in that sense predictable, meaning that Rosetta results correspond to typical behaviour for this comet. The gas production (for CN at least) is highly asymmetric with respect to perihelion, as our upper limits are below the measured production rates for similar distances post-perihelion in previous orbits.

    Based on observations made with ESO telescopes at the La Silla Paranal Observatory under programme IDs 592.C-0924, 093.C-0593, 094.C-0054, and at Gemini South under GS-2014B-Q-15 and GS-2014B-Q-76.

  57. Pasachoff, J., Person, M., Bosh, A., Sickafoose, A., Zuluaga, C., Kosiarek, M., Levine, S., Osip, D., Schiff, A., Seeger, C., Babcock, B., Rojo, P., Servajean, E., 2016, AJ, 151, 97, Trio of Stellar Occultations by Pluto One Year Prior to New Horizons' Arrival
    We observed occultations by Pluto during a predicted series of events in 2014 July with the 1 m telescope of the Mt. John Observatory in New Zealand. The predictions were based on updated astrometry obtained in the previous months at the USNO, CTIO, and Lowell Observatories. We successfully detected occultations by Pluto of an R = 18 mag star on July 23 (14:23:32 00:00:04 UTC to 14:25:30 00:00:04 UTC), with a drop of 75% of the unocculted stellar signal, and of an R = 17 star on July 24 (11:41:30 00:00:08 UTC to 11:43:28 00:00:08 UTC), with a drop of 80% of the unocculted stellar signal, both with 20 s exposures with our frame-transfer Portable Occultation, Eclipse, and Transit System. Since Pluto had a geocentric velocity of 22.51 km s-1 on July 23 and 22.35 km s-1 on July 24, these intervals yield limits on the chord lengths (surface and lower atmosphere) of 2700 130 km and 2640 250 km, respectively, indicating that the events were near central, and therefore provide astrometric constraints on the prediction method. Our coordinated observations with the 4 m AAT in Australia on July 23 and the 6.5 m Magellan/Clay on Las Campanas, the 4.1 m Southern Astrophysical Research Telescope on Cerro Pachon, the 2.5 m DuPont on Las Campanas (LCO), the 0.6 m SARA-South on Cerro Tololo of the Southeastern Association for Research in Astronomy (SARA), the MPI/ESO 2.2 m on La Silla, and the 0.45 m Cerro Calan telescope and 0.36 telescope in Constitucion in Chile on July 27 and 31, which would have provided higher-cadence observations for studies of Plutos atmosphere, were largely foiled by clouds, but led to detection with the LCO Magellan/Clay and DuPont Telescopes on July 31 of the grazing occultation of a previously unknown 15th-magnitude star, completing the trio of occultations successfully observed and reported in this paper.
  58. Mommert, M., Trilling, D., Borth, D., Jedicke, R., Butler, N., Reyes-Ruiz, M., Pichardo, B., Petersen, E., Axelrod, T., Moskovitz, N., 2016, AJ, 151, 98, First Results from the Rapid-response Spectrophotometric Characterization of Near-Earth Objects using UKIRT
    Using the Wide Field Camera for the United Kingdom Infrared Telescope (UKIRT), we measure the near-infrared colors of near-Earth objects (NEOs) in order to put constraints on their taxonomic classifications. The rapid-response character of our observations allows us to observe NEOs when they are close to the Earth and bright. Here we present near-infrared color measurements of 86 NEOs, most of which were observed within a few days of their discovery, allowing us to characterize NEOs with diameters of only a few meters. Using machine-learning methods, we compare our measurements to existing asteroid spectral data and provide probabilistic taxonomic classifications for our targets. Our observations allow us to distinguish between S-complex, C/X-complex, D-type, and V-type asteroids. Our results suggest that the fraction of S-complex asteroids in the whole NEO population is lower than the fraction of ordinary chondrites in the meteorite fall statistics. Future data obtained with UKIRT will be used to investigate the significance of this discrepancy.
  59. Haywood, R., Collier Cameron, A., Unruh, Y., Lovis, C., Lanza, A., Llama, J., Deleuil, M., Fares, R., Gillon, M., Moutou, C., Pepe, F., Pollacco, D., Queloz, D., Segransan, D., 2016, MNRAS, 457, 3637, The Sun as a planet-host star: proxies from SDO images for HARPS radial-velocity variations
    The Sun is the only star whose surface can be directly resolved at high resolution, and therefore constitutes an excellent test case to explore the physical origin of stellar radial-velocity (RV) variability. We present HARPS observations of sunlight scattered off the bright asteroid 4/Vesta, from which we deduced the Sun's activity-driven RV variations. In parallel, the Helioseismic and Magnetic Imager instrument on board the Solar Dynamics Observatory provided us with simultaneous high spatial resolution magnetograms, Dopplergrams and continuum images of the Sun in the Fe I 6173 A line. We determine the RV modulation arising from the suppression of granular blueshift in magnetized regions and the flux imbalance induced by dark spots and bright faculae. The rms velocity amplitudes of these contributions are 2.40 and 0.41 m s-1, respectively, which confirms that the inhibition of convection is the dominant source of activity-induced RV variations at play, in accordance with previous studies. We find the Doppler imbalances of spot and plage regions to be only weakly anticorrelated. Light curves can thus only give incomplete predictions of convective blueshift suppression. We must instead seek proxies that track the plage coverage on the visible stellar hemisphere directly. The chromospheric flux index R^' }_{HK} derived from the HARPS spectra performs poorly in this respect, possibly because of the differences in limb brightening/darkening in the chromosphere and photosphere. We also find that the activity-driven RV variations of the Sun are strongly correlated with its full-disc magnetic flux density, which may become a useful proxy for activity-related RV noise.
  60. Polishook, D., Moskovitz, N., Binzel, R., Burt, B., DeMeo, F., Hinkle, M., Lockhart, M., Mommert, M., Person, M., Thirouin, A., Thomas, C., Trilling, D., Willman, M., Aharonson, O., 2016, Icar, 267, 243, A 2 km-size asteroid challenging the rubble-pile spin barrier - A case for cohesion
    The rubble pile spin barrier is an upper limit on the rotation rate of asteroids larger than 200-300 m. Among thousands of asteroids with diameters larger than 300 m, only a handful of asteroids are known to rotate faster than 2.0 h, all are in the sub-km range (0.6 km). Here we present photometric measurements suggesting that (60716) 2000 GD65, an S-complex, inner-main belt asteroid with a relatively large diameter of 2.3-0.7+0.6km , completes one rotation in 1.9529 0.0002h . Its unique diameter and rotation period allow us to examine scenarios about asteroid internal structure and evolution: a rubble pile bound only by gravity; a rubble-pile with strong cohesion; a monolithic structure; an asteroid experiencing mass shedding; an asteroid experiencing YORP spin-up/down; and an asteroid with a unique octahedron shape results with a four-peak lightcurve and a 3.9 h period. We find that the most likely scenario includes a lunar-like cohesion that can prevent (60716) 2000 GD65 from disrupting without requiring a monolithic structure or a unique shape. Due to the uniqueness of (60716) 2000 GD65, we suggest that most asteroids typically have smaller cohesion than that of lunar regolith.
  61. Holler, B., Young, L., Grundy, W., Olkin, C., 2016, Icar, 267, 255, On the surface composition of Triton's southern latitudes
    We present the results of an investigation to determine the longitudinal (zonal) distributions and temporal evolution of ices on the surface of Triton. Between 2002 and 2014, we obtained 63 nights of near-infrared (0.67-2.55 m) spectra using the SpeX instrument at NASA's Infrared Telescope Facility (IRTF). Triton has spectral features in this wavelength region from N2, CO, CH4, CO2, and H2O. Absorption features of ethane (C2H6) and 13CO are coincident at 2.405 m, a feature that we detect in our spectra. We calculated the integrated band area (or fractional band depth in the case of H2O) in each nightly average spectrum, constructed longitudinal distributions, and quantified temporal evolution for each of the chosen absorption bands. The volatile ices (N2, CO, CH4) show significant variability over one Triton rotation and have well-constrained longitudes of peak absorption. The non-volatile ices (CO2, H2O) show poorly-constrained peak longitudes and little variability. The longitudinal distribution of the 2.405 m band shows little variability over one Triton rotation and is 97 44 and 92 44 out of phase with the 1.58 m and 2.35 m CO bands, respectively. This evidence indicates that the 2.405 m band is due to absorption from non-volatile ethane. CH4 absorption increased over the period of the observations while absorption from all other ices showed no statistically significant change. We conclude from these results that the southern latitudes of Triton are currently dominated by non-volatile ices and as the sub-solar latitude migrates northwards, a larger quantity of volatile ice is coming into view.
  62. Mann, A., Feiden, G., Gaidos, E., Boyajian, T., von Braun, K., 2016, ApJ, 819, 87, Erratum: How to Constrain Your M Dwarf: Measuring Effective Temperature, Bolometric Luminosity, Mass, and Radius (ApJ, 804, 64)
    No abstract found.
  63. Weaver, H., Buie, M., Buratti, B., Grundy, W., Lauer, T., Olkin, C., Parker, A., Porter, S., Showalter, M., Spencer, J., Stern, S., Verbiscer, A., McKinnon, W., Moore, J., Robbins, S., Schenk, P., Singer, K., Barnouin, O., Cheng, A., Ernst, C., Lisse, C., Jennings, D., Lunsford, A., Reuter, D., Hamilton, D., Kaufmann, D., Ennico, K., Young, L., Beyer, R., Binzel, R., Bray, V., Chaikin, A., Cook, J., Cruikshank, D., Dalle Ore, C., Earle, A., Gladstone, G., Howett, C., Linscott, I., Nimmo, F., Parker, J., Philippe, S., Protopapa, S., Reitsema, H., Schmitt, B., Stryk, T., Summers, M., Tsang, C., Throop, H., White, O., Zangari, A., 2016, Sci, 351, aae0030, The small satellites of Pluto as observed by New Horizons
    The New Horizons mission has provided resolved measurements of Plutos moons Styx, Nix, Kerberos, and Hydra. All four are small, with equivalent spherical diameters of ~40 kilometers for Nix and Hydra and ~10 kilometers for Styx and Kerberos. They are also highly elongated, with maximum to minimum axis ratios of ~2. All four moons have high albedos (~50 to 90%) suggestive of a water-ice surface composition. Crater densities on Nix and Hydra imply surface ages of at least 4 billion years. The small moons rotate much faster than synchronous, with rotational poles clustered nearly orthogonal to the common pole directions of Pluto and Charon. These results reinforce the hypothesis that the small moons formed in the aftermath of a collision that produced the Pluto-Charon binary.
  64. Moore, J., McKinnon, W., Spencer, J., Howard, A., Schenk, P., Beyer, R., Nimmo, F., Singer, K., Umurhan, O., White, O., Stern, S., Ennico, K., Olkin, C., Weaver, H., Young, L., Binzel, R., Buie, M., Buratti, B., Cheng, A., Cruikshank, D., Grundy, W., Linscott, I., Reitsema, H., Reuter, D., Showalter, M., Bray, V., Chavez, C., Howett, C., Lauer, T., Lisse, C., Parker, A., Porter, S., Robbins, S., Runyon, K., Stryk, T., Throop, H., Tsang, C., Verbiscer, A., Zangari, A., Chaikin, A., Wilhelms, D., Bagenal, F., Gladstone, G., Andert, T., Andrews, J., Banks, M., Bauer, B., Bauman, J., Barnouin, O., Bedini, P., Beisser, K., Bhaskaran, S., Birath, E., Bird, M., Bogan, D., Bowman, A., Brozovic, M., Bryan, C., Buckley, M., Bushman, S., Calloway, A., Carcich, B., Conard, S., Conrad, C., Cook, J., Custodio, O., Ore, C., Deboy, C., Dischner, Z., Dumont, P., Earle, A., Elliott, H., Ercol, J., Ernst, C., Finley, T., Flanigan, S., Fountain, G., Freeze, M., Greathouse, T., Green, J., Guo, Y., Hahn, M., Hamilton, D., Hamilton, S., Hanley, J., Harch, A., Hart, H., Hersman, C., Hill, A., Hill, M., Hinson, D., Holdridge, M., Horanyi, M., Jackman, C., Jacobson, R., Jennings, D., Kammer, J., Kang, H., Kaufmann, D., Kollmann, P., Krimigis, S., Kusnierkiewicz, D., Lee, J., Lindstrom, K., Lunsford, A., Mallder, V., Martin, N., McComas, D., McNutt, R., Mehoke, D., Mehoke, T., Melin, E., Mutchler, M., Nelson, D., Nunez, J., Ocampo, A., Owen, W., Paetzold, M., Page, B., Parker, J., Pelletier, F., Peterson, J., Pinkine, N., Piquette, M., Protopapa, S., Redfern, J., Roberts, J., Rogers, G., Rose, D., Retherford, K., Ryschkewitsch, M., Schindhelm, R., Sepan, B., Soluri, M., Stanbridge, D., Steffl, A., Strobel, D., Summers, M., Szalay, J., Tapley, M., Taylor, A., Taylor, H., Tyler, G., Versteeg, M., Vincent, M., Webbert, R., Weidner, S., Weigle, G., Whittenburg, K., Williams, B., Williams, K., Williams, S., Woods, W., Zirnstein, E., 2016, Sci, 351, 1284, The geology of Pluto and Charon through the eyes of New Horizons
    NASAs New Horizons spacecraft has revealed the complex geology of Pluto and Charon. Plutos encounter hemisphere shows ongoing surface geological activity centered on a vast basin containing a thick layer of volatile ices that appears to be involved in convection and advection, with a crater retention age no greater than ~10 million years. Surrounding terrains show active glacial flow, apparent transport and rotation of large buoyant water-ice crustal blocks, and pitting, the latter likely caused by sublimation erosion and/or collapse. More enigmatic features include tall mounds with central depressions that are conceivably cryovolcanic and ridges with complex bladed textures. Pluto also has ancient cratered terrains up to ~4 billion years old that are extensionally faulted and extensively mantled and perhaps eroded by glacial or other processes. Charon does not appear to be currently active, but experienced major extensional tectonism and resurfacing (probably cryovolcanic) nearly 4 billion years ago. Impact crater populations on Pluto and Charon are not consistent with the steepest impactor size-frequency distributions proposed for the Kuiper belt.
  65. Grundy, W., Binzel, R., Buratti, B., Cook, J., Cruikshank, D., Dalle Ore, C., Earle, A., Ennico, K., Howett, C., Lunsford, A., Olkin, C., Parker, A., Philippe, S., Protopapa, S., Quirico, E., Reuter, D., Schmitt, B., Singer, K., Verbiscer, A., Beyer, R., Buie, M., Cheng, A., Jennings, D., Linscott, I., Parker, J., Schenk, P., Spencer, J., Stansberry, J., Stern, S., Throop, H., Tsang, C., Weaver, H., Weigle, G., Young, L., 2016, Sci, 351, aad9189, Surface compositions across Pluto and Charon
    The New Horizons spacecraft mapped colors and infrared spectra across the encounter hemispheres of Pluto and Charon. The volatile methane, carbon monoxide, and nitrogen ices that dominate Plutos surface have complicated spatial distributions resulting from sublimation, condensation, and glacial flow acting over seasonal and geological time scales. Plutos water ice bedrock was also mapped, with isolated outcrops occurring in a variety of settings. Plutos surface exhibits complex regional color diversity associated with its distinct provinces. Charons color pattern is simpler, dominated by neutral low latitudes and a reddish northern polar region. Charons near-infrared spectra reveal highly localized areas with strong ammonia absorption tied to small craters with relatively fresh-appearing impact ejecta.
  66. Kohn, S., Shkolnik, E., Weinberger, A., Carlberg, J., Llama, J., 2016, ApJ, 820, 2, Searching for Spectroscopic Binaries within Transition Disk Objects
    Transition disks (TDs) are intermediate stage circumstellar disks characterized by an inner gap within the disk structure. To test whether these gaps may have been formed by closely orbiting, previously undetected stellar companions, we collected high-resolution optical spectra of 31 TD objects to search for spectroscopic binaries (SBs). Twenty-four of these objects are in Ophiuchus and seven are within the Coronet, Corona Australis, and Chameleon I star-forming regions. We measured radial velocities for multiple epochs, obtaining a median precision of 400 ms-1. We identified double-lined SB SSTc2d J163154.7-250324 in Ophiuchus, which we determined to be composed of a K7(0.5) and a K9(0.5) star, with orbital limits of a < 0.6 au and P < 150 days. This results in an SB fraction of {0.04}-0.03+0.12 in Ophiuchus, which is consistent with other spectroscopic surveys of non-TD objects in the region. This similarity suggests that TDs are not preferentially sculpted by the presence of close binaries and that planet formation around close binaries may take place over similar timescales to that around single stars.

    This paper is based on data gathered with the 6.5 m Clay Telescope located at Las Campanas Observatory, Chile.

  67. Alvarez-Candal, A., Pinilla-Alonso, N., Ortiz, J., Duffard, R., Morales, N., Santos-Sanz, P., Thirouin, A., Silva, J., 2016, A&A, 586, A155, Absolute magnitudes and phase coefficients of trans-Neptunian objects
    Context. Accurate measurements of diameters of trans-Neptunian objects (TNOs) are extremely difficult to obtain. Thermal modeling can provide good results, but accurate absolute magnitudes are needed to constrain the thermal models and derive diameters and geometric albedos. The absolute magnitude, HV, is defined as the magnitude of the object reduced to unit helio- and geocentric distances and a zero solar phase angle and is determined using phase curves. Phase coefficients can also be obtained from phase curves. These are related to surface properties, but only few are known.
    Aims: Our objective is to measure accurate V-band absolute magnitudes and phase coefficients for a sample of TNOs, many of which have been observed and modeled within the program "TNOs are cool", which is one of the Herschel Space Observatory key projects.
    Methods: We observed 56 objects using the V and R filters. These data, along with those available in the literature, were used to obtain phase curves and measure V-band absolute magnitudes and phase coefficients by assuming a linear trend of the phase curves and considering a magnitude variability that is due to the rotational light-curve.
    Results: We obtained 237 new magnitudes for the 56 objects, six of which were without previously reported measurements. Including the data from the literature, we report a total of 110 absolute magnitudes with their respective phase coefficients. The average value of HV is 6.39, bracketed by a minimum of 14.60 and a maximum of -1.12. For the phase coefficients we report a median value of 0.10 mag per degree and a very large dispersion, ranging from -0.88 up to 1.35 mag per degree.
  68. Hanus, J., Durech, J., Oszkiewicz, D., Behrend, R., Carry, B., Delbo, M., Adam, O., Afonina, V., Anquetin, R., Antonini, P., Arnold, L., Audejean, M., Aurard, P., Bachschmidt, M., Baduel, B., Barbotin, E., Barroy, P., Baudouin, P., Berard, L., Berger, N., Bernasconi, L., Bosch, J., Bouley, S., Bozhinova, I., Brinsfield, J., Brunetto, L., Canaud, G., Caron, J., Carrier, F., Casalnuovo, G., Casulli, S., Cerda, M., Chalamet, L., Charbonnel, S., Chinaglia, B., Cikota, A., Colas, F., Coliac, J., Collet, A., Coloma, J., Conjat, M., Conseil, E., Costa, R., Crippa, R., Cristofanelli, M., Damerdji, Y., Debackere, A., Decock, A., Dehais, Q., Deleage, T., Delmelle, S., Demeautis, C., Drozdz, M., Dubos, G., Dulcamara, T., Dumont, M., Durkee, R., Dymock, R., Escalante del Valle, A., Esseiva, N., Esseiva, R., Esteban, M., Fauchez, T., Fauerbach, M., Fauvaud, M., Fauvaud, S., Forne, E., Fournel, C., Fradet, D., Garlitz, J., Gerteis, O., Gillier, C., Gillon, M., Giraud, R., Godard, J., Goncalves, R., Hamanowa, H., Hamanowa, H., Hay, K., Hellmich, S., Heterier, S., Higgins, D., Hirsch, R., Hodosan, G., Hren, M., Hygate, A., Innocent, N., Jacquinot, H., Jawahar, S., Jehin, E., Jerosimic, L., Klotz, A., Koff, W., Korlevic, P., Kosturkiewicz, E., Krafft, P., Krugly, Y., Kugel, F., Labrevoir, O., Lecacheux, J., Lehky, M., Leroy, A., Lesquerbault, B., Lopez-Gonzales, M., Lutz, M., Mallecot, B., Manfroid, J., Manzini, F., Marciniak, A., Martin, A., Modave, B., Montaigut, R., Montier, J., Morelle, E., Morton, B., Mottola, S., Naves, R., Nomen, J., Oey, J., Ogoza, W., Paiella, M., Pallares, H., Peyrot, A., Pilcher, F., Pirenne, J., Piron, P., Polinska, M., Polotto, M., Poncy, R., Previt, J., Reignier, F., Renauld, D., Ricci, D., Richard, F., Rinner, C., Risoldi, V., Robilliard, D., Romeuf, D., Rousseau, G., Roy, R., Ruthroff, J., Salom, P., Salvador, L., Sanchez, S., Santana-Ros, T., Scholz, A., Sene, G., Skiff, B., Sobkowiak, K., Sogorb, P., Soldan, F., Spiridakis, A., Splanska, E., Sposetti, S., Starkey, D., Stephens, R., Stiepen, A., Stoss, R., Strajnic, J., Teng, J., Tumolo, G., Vagnozzi, A., Vanoutryve, B., Vugnon, J., Warner, B., Waucomont, M., Wertz, O., Winiarski, M., Wolf, M., 2016, A&A, 586, A108, New and updated convex shape models of asteroids based on optical data from a large collaboration network
    Context. Asteroid modeling efforts in the last decade resulted in a comprehensive dataset of almost 400 convex shape models and their rotation states. These efforts already provided deep insight into physical properties of main-belt asteroids or large collisional families. Going into finer detail (e.g., smaller collisional families, asteroids with sizes 20 km) requires knowledge of physical parameters of more objects.
    Aims: We aim to increase the number of asteroid shape models and rotation states. Such results provide important input for further studies, such as analysis of asteroid physical properties in different populations, including smaller collisional families, thermophysical modeling, and scaling shape models by disk-resolved images, or stellar occultation data. This provides bulk density estimates in combination with known masses, but also constrains theoretical collisional and evolutional models of the solar system.
    Methods: We use all available disk-integrated optical data (I.e., classical dense-in-time photometry obtained from public databases and through a large collaboration network as well as sparse-in-time individual measurements from a few sky surveys) as input for the convex inversion method, and derive 3D shape models of asteroids together with their rotation periods and orientations of rotation axes. The key ingredient is the support of more that 100 observers who submit their optical data to publicly available databases.
    Results: We present updated shape models for 36 asteroids, for which mass estimates are currently available in the literature, or for which masses will most likely be determined from their gravitational influence on smaller bodies whose orbital deflections will be observed by the ESA Gaia astrometric mission. Moreover, we also present new shape model determinations for 250 asteroids, including 13 Hungarias and three near-Earth asteroids. The shape model revisions and determinations were enabled by using additional optical data from recent apparitions for shape optimization.
  69. Thomas, C., Abell, P., Castillo-Rogez, J., Moskovitz, N., Mueller, M., Reddy, V., Rivkin, A., Ryan, E., Stansberry, J., 2016, PASP, 128, 018002, Observing Near-Earth Objects with the James Webb Space Telescope
    The James Webb Space Telescope (JWST) has the potential to enhance our understanding of near-Earth objects (NEOs). We present results of investigations into the observability of NEOs given the nominal observing requirements of JWST on elongation (85-135) and non-sidereal rates (<30 mas s-1). We find that approximately 75% of NEOs can be observed in a given year. However, observers will need to wait for appropriate observing windows. We find that JWST can easily execute photometric observations of meter-sized NEOs that will enhance our understanding of the small NEO population.
  70. Keszthelyi, L., Grundy, W., Stansberry, J., Sivaramakrishnan, A., Thatte, D., Gudipati, M., Tsang, C., Greenbaum, A., McGruder, C., 2016, PASP, 128, 018006, Observing Outer Planet Satellites (Except Titan) with the James Webb Space Telescope: Science Justification and Observational Requirements
    The James Webb Space Telescope (JWST) will allow observations with a unique combination of spectral, spatial, and temporal resolution for the study of outer planet satellites within our Solar System. We highlight the infrared spectroscopy of icy moons and temporal changes on geologically active satellites as two particularly valuable avenues of scientific inquiry. While some care must be taken to avoid saturation issues, JWST has observation modes that should provide excellent infrared data for such studies.
  71. Kelley, M., Woodward, C., Bodewits, D., Farnham, T., Gudipati, M., Harker, D., Hines, D., Knight, M., Kolokolova, L., Li, A., de Pater, I., Protopapa, S., Russell, R., Sitko, M., Wooden, D., 2016, PASP, 128, 018009, Cometary Science with the James Webb Space Telescope
    The James Webb Space Telescope (JWST), as the largest space-based astronomical observatory with near- and mid-infrared instrumentation, will elucidate many mysterious aspects of comets. We summarize four cometary science themes especially suited for this telescope and its instrumentation: the drivers of cometary activity, comet nucleus heterogeneity, water ice in comae and on surfaces, and activity in faint comets and main belt asteroids. With JWST, we can expect the most distant detections of gas, especially CO2, in what we now consider to be only moderately bright comets. For nearby comets, coma dust properties can be simultaneously studied with their driving gases, measured simultaneously with the same instrument or contemporaneously with another. Studies of water ice and gas in the distant Solar System will help us test our understanding of cometary interiors, and coma evolution. The question of cometary activity in main belt comets will be further explored with the possibility of a direct detection of coma gas. We explore the technical approaches to these science cases and provide simple tools for estimating comet dust and gas brightness. Finally, we consider the effects of the observatory's non-sidereal tracking limits and provide a list of potential comet targets during the first five years of the mission.
  72. Parker, A., Pinilla-Alonso, N., Santos-Sanz, P., Stansberry, J., Alvarez-Candal, A., Bannister, M., Benecchi, S., Cook, J., Fraser, W., Grundy, W., Guilbert, A., Merline, B., Moullet, A., Mueller, M., Olkin, C., Ragozzine, D., 2016, PASP, 128, 018010, Physical Characterization of TNOs with the James Webb Space Telescope
    Studies of the physical properties of trans-Neptunian objects (TNOs) are a powerful probe into the processes of planetesimal formation and solar system evolution. James Webb Space Telescope (JWST) will provide unique new capabilities for such studies. Here, we outline where the capabilities of JWST open new avenues of investigation, potentially valuable observations and surveys, and conclude with a discussion of community actions that may serve to enhance the eventual science return of JWST's TNO observations.
  73. Llama, J., Shkolnik, E., 2016, ApJ, 817, 81, Transiting the Sun. II. The Impact of Stellar Activity on Ly Transits
    High-energy observations of the Sun provide an opportunity to test the limits of our ability to accurately measure the properties of transiting exoplanets in the presence of stellar activity. Here we insert the transit of a hot Jupiter into continuous disk integrated data of the Sun in Ly from NASAs Solar Dynamics Observatory/EVE instrument to assess the impact of stellar activity on the measured planet-to-star radius ratio (Rp/R). In 75% of our simulated light curves, we measure the correct radius ratio; however, incorrect values can be measured if there is significant short-term variability in the light curve. The maximum measured value of Rp/R is 50% larger than the input value, which is much smaller than the large Ly transit depths that have been reported in the literature, suggesting that for stars with activity levels comparable to the Sun, stellar activity alone cannot account for these deep transits. We ran simulations without a transit and found that stellar activity cannot mimic the Ly transit of 55 Cancari b, strengthening the conclusion that this planet has a partially transiting exopshere. We were able to compare our simulations to more active stars by artificially increasing the variability in the Solar Ly light curve. In the higher variability data, the largest value of Rp/R we measured is <3 the input value, which again is not large enough to reproduce the Ly transit depth reported for the more active stars HD 189733 and GJ 436, supporting the interpretation that these planets have extended atmospheres and possible cometary tails.
  74. Polishook, D., Moskovitz, N., 2016, IAUS, 318, 193, Searching for color variation on fast rotating asteroids with simultaneous V-J observations
    Boulders, rocks and regolith on fast rotating asteroids (<2.5 hours) are modeled to slide towards the equator due to a strong centrifugal force and a low cohesion force. As a result, regions of fresh subsurface material can be exposed. Therefore, we searched for color variation on small and fast rotating asteroids. We describe a novel technique in which the asteroid is simultaneously observed in the visible and near-IR wavelength range. In this technique, brightness changes due to atmospheric extinction effects can be calibrated across the visible and near-IR images. We use V- and J-band filters since the distinction in color between weathered and unweathered surfaces on ordinary chondrite-like bodies is most prominent at these wavelengths and can reach ~25%. To test our method, we observed 3 asteroids with Cerro Tololo's 1.3 m telescope. We find ~5% variation of the mean V-J color, but do not find any clearly repeating color signature through multiple rotations. This suggests that no landslides occurred within the timescale of space weathering, or that Landslides occurred but the exposed patches are too small for the measurements' uncertainty.
  75. Flagg, L., Shkolnik, E., Weinberger, A., Bowler, B., Kraus, A., Liu, M., 2016, IAUS, 314, 65, A New, Young, Low-Mass Spectroscopic Binary Without a Home
    We have discovered that 2MASS 08355977-3042306 is an accreting K7, double-lined, spectroscopic binary younger than ~20 Myr. The age of a dispersed young star can best be determined if it is a member of a known young moving group. However, the three dimensional space velocities (UVW) we calculate using radial velocity measurements, proper motions, and plausible photometric distances make membership in any known young moving group unlikely.
  76. Plavchan, P., Gao, P., Gagne, J., Furlan, E., Brinkworth, C., Bottom, M., Tanner, A., Anglada-Escude, G., White, R., Davison, C., Mills, S., Beichman, C., Johnson, J., Ciardi, D., Wallace, K., Mennesson, B., Vasisht, G., Prato, L., Kane, S., Crawford, S., Crawford, T., Sung, K., Drouin, B., Lin, S., Leifer, S., Catanzarite, J., Henry, T., von Braun, K., Walp, B., Geneser, C., Ogden, N., Stufflebeam, A., Pohl, G., Regan, J., 2016, IAUS, 314, 286, Precise Near-Infrared Radial Velocities
    We present the results of two 2.3 m near-infrared (NIR) radial velocity (RV) surveys to detect exoplanets around 36 nearby and young M dwarfs. We use the CSHELL spectrograph (R ~ 46,000) at the NASA InfraRed Telescope Facility (IRTF), combined with an isotopic methane absorption gas cell for common optical path relative wavelength calibration. We have developed a sophisticated RV forward modeling code that accounts for fringing and other instrumental artifacts present in the spectra. With a spectral grasp of only 5 nm, we are able to reach long-term radial velocity dispersions of ~20-30 m s-1 on our survey targets.
  77. Lorenzi, V., Pinilla-Alonso, N., Licandro, J., Cruikshank, D., Grundy, W., Binzel, R., Emery, J., 2016, A&A, 585, A131, The spectrum of Pluto, 0.40-0.93 m. I. Secular and longitudinal distribution of ices and complex organics
    Context. During the past 30 years the surface of Pluto has been characterized and its variability monitored through continuous near-infrared spectroscopic observations. But in the visible range only a few data are available.
    Aims: The aim of this work is to define Pluto's relative reflectance in the visible range to characterize the different components of its surface, and to provide ground based observations in support of the New Horizons mission.
    Methods: We observed Pluto on six nights between May and July 2014 with the imager/spectrograph ACAM at the William Herschel Telescope (La Palma, Spain). The six spectra obtained cover a whole rotation of Pluto (Prot = 6.4 days). For all the spectra, we computed the spectral slope and the depth of the absorption bands of methane ice between 0.62 and 0.90 m. To search for shifts in the center of the methane bands, which are associated with dilution of CH4 in N2, we compared the bands with reflectances of pure methane ice.
    Results: All the new spectra show the methane ice absorption bands between 0.62 and 0.90 m. Computation of the depth of the band at 0.62 m in the new spectra of Pluto and in the spectra of Makemake and Eris from the literature, allowed us to estimate the Lambert coefficient at this wavelength at temperatures of 30 K and 40 K, which has never been measured before. All the detected bands are blueshifted with respect to the position for pure methane ice, with minimum shifts correlated to the regions where the abundance of methane is higher. This could be indicative of a dilution of CH4:N2 that is more saturated in CH4. The longitudinal and secular variations in the parameters measured in the spectra are in accordance with results previously reported in the literature and with the distribution of the dark and bright materials that show the Pluto's color maps from New Horizons.
  78. Cigan, P., Young, L., Cormier, D., Lebouteiller, V., Madden, S., Hunter, D., Brinks, E., Elmegreen, B., Schruba, A., Heesen, V., the Little Things Team, 2016, AJ, 151, 14, Herschel Spectroscopic Observations of Little Things Dwarf Galaxies
    We present far-infrared (FIR) spectral line observations of five galaxies from the Little Things sample: DDO 69, DDO 70, DDO 75, DDO 155, and WLM. While most studies of dwarfs focus on bright systems or starbursts due to observational constraints, our data extend the observed parameter space into the regime of low surface brightness dwarf galaxies with low metallicities and moderate star formation rates. Our targets were observed with Herschel at the [C II] 158 m, [O I] 63 m, [O III] 88 m, and [N II] 122 m emission lines using the PACS Spectrometer. These high-resolution maps allow us for the first time to study the FIR properties of these systems on the scales of larger star-forming complexes. The spatial resolution in our maps, in combination with star formation tracers, allows us to identify separate photodissociation regions (PDRs) in some of the regions we observed. Our systems have widespread [C II] emission that is bright relative to continuum, averaging near 0.5% of the total infrared (TIR) budgethigher than in solar-metallicity galaxies of other types. [N II] is weak, suggesting that the [C II] emission in our galaxies comes mostly from PDRs instead of the diffuse ionized interstellar medium (ISM). These systems exhibit efficient cooling at low dust temperatures, as shown by ([O I]+[C II])/TIR in relation to 60 m/100 m, and low [O I]/[C II] ratios which indicate that [C II] is the dominant coolant of the ISM. We observe [O III]/[C II] ratios in our galaxies that are lower than those published for other dwarfs, but similar to levels noted in spirals.
  79. 78 publications and 2598 citations in 2016.

78 publications and 2598 citations total.