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Recent research involving Lowell Observatory staff
(All publications with publication dates in September 2025)

This is a work ever in progress.

(Pulled from ADS* by sel on 2025-09-15)

*We are grateful for all the effort that went into making The SAO/NASA Astrophysics Data System (ADS) possible. The ADS is operated by the Smithsonian Astrophysical Observatory under NASA Cooperative Agreement NNX16AC86A and can be found at: https://ui.adsabs.harvard.edu/

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Years: 2025 Bottom

    2025

  1. Kareta, T., Champagne, C., McClure, L., Emery, J., Sharkey, B., Bauer, J., Connelley, M., Rayner, J., Thomas, C., Reddy, V., Firgard, M., 2025, ApJL, 990, L65, Near-discovery Observations of Interstellar Comet 3I/ATLAS with the NASA Infrared Telescope Facility
    Interstellar objects are comets and asteroids that formed around other stars but were ejected before they could accrete into exoplanets. They therefore represent a rare opportunity to compare the the building blocks of planets in the solar system to those in other stellar systems. The third interstellar object, 3I/ATLAS, is the newest, brightest, potentially largest, and fastest member of this population. We report observations of 3I/ATLAS taken on 2025 July 3 and 4 with the NASA Infrared Telescope Facility just days after its discovery. In r' -band imaging with 'Opihi, we see no obvious lightcurve variability and derive a g'i' color of 0.98 0.03, which is consistent in spectral slope to other near-discovery observations. We obtained the first near-infrared (NIR) reflectance spectrum of 3I/ATLAS with SpeX. The visible color and NIR spectrum show a linear, red visible slope, a somewhat less red slope between 0.7 and 1.1 m, and a neutral or slightly blue slope at longer wavelengths. Challenges in modeling the reflectivity of 3I may indicate that this comet has a complex grain size distribution, grain compositions unlike solar system comets, or both. Like 2I/Borisov, there are no obvious signatures of water ice in the coma of 3I/ATLAS. Observations closer to perihelion will help elucidate whether 3I has less water than anticipated or whether the interstellar objects might retain and release their ices somewhat differently from solar system comets.
  2. Yee, S., Winn, J., Hartman, J., Rodriguez, J., Zhou, G., Latham, D., Quinn, S., Bieryla, A., Collins, K., Eastman, J., Collins, K., Conti, D., Jensen, E., Baker, D., Barkaoui, K., Basturk, O., Battley, M., Bayliss, D., Beatty, T., Beletsky, Y., Belinski, A., Benkhaldoun, Z., Benni, P., Bosch-Cabot, P., Briceno, C., Brudny, A., Burleigh, M., Butler, R., Chairetas, S., Chontos, A., Christiansen, J., Ciardi, D., Clark, C., Cloutier, R., Craig, M., Crane, J., Dowling, N., Dressing, C., Emmanuel, J., Evans, P., Everett, M., Fernandez-Rodriguez, G., Fernandez Fernandez, J., Fores-Toribio, R., Fortenbach, C., Fukui, A., Furlan, E., Gan, T., Ghachoui, M., Giacalone, S., Gill, S., Gillon, M., Hall, K., Hayashi, Y., Hedges, C., Higuera, J., Hintz, E., Hirsch, L., Holcomb, R., Horne, K., Grau Horta, F., Howard, A., Howell, S., Isaacson, H., Jenkins, J., Kagetani, T., Kamler, J., Kendall, A., Korth, J., Kroft, M., Lacedelli, G., Laloum, D., Law, N., de Leon, J., Levine, A., Lewin, P., Logsdon, S., Lund, M., Madsen, M., Mann, A., Mann, C., Maslennikova, N., Matutano, S., McCormack, M., McLeod, K., Michaels, E., Mireles, I., Mori, M., Munoz, J., Murgas, F., Narita, N., O'Brien, S., Odden, C., Palle, E., Patel, Y., Plavchan, P., Polanski, A., Popowicz, A., Radford, D., Reed, P., Relles, H., Rice, M., Ricker, G., Safonov, B., Savel, A., Schulte, J., Schwarz, R., Schweiker, H., Seager, S., Sefako, R., Shectman, S., Shporer, A., Stephens, D., Stockdale, C., Striegel, S., Tan, T., Teske, J., Timmermans, M., Ulmer-Moll, S., Wang, G., Wheatley, P., Yalcinkaya, S., Zambelli, R., Van Zandt, J., Ziegler, C., 2025, ApJS, 280, 30, The TESS Grand Unified Hot Jupiter Survey. III. Thirty More Giant Planets
    We present the discovery of 30 transiting giant planets that were initially detected using data from NASA's Transiting Exoplanet Survey Satellite mission. These new planets orbit relatively bright (G 12.5) FGK host stars with orbital periods between 1.6 and 8.2 days, and have radii between 0.9 and 1.7 Jupiter radii. We performed follow-up ground-based photometry, high angular resolution imaging, high-resolution spectroscopy, and radial velocity monitoring for each of these objects to confirm that they are planets and determine their masses and other system parameters. The planets' masses span more than an order of magnitude (0.17 MJ < Mp < 3.3 MJ). For two planets, TOI-3593 b and TOI-4961 b, we measured significant nonzero eccentricities of 0.110.03+0.05 and 0.180.05+0.04 , respectively, while for the other planets, the data typically provide a 1 upper bound of 0.15 on the eccentricity. These discoveries represent a major step toward assembling a complete, magnitude-limited sample of transiting hot Jupiters around FGK stars. *This paper includes data gathered with the 6.5 m Magellan Telescopes located at Las Campanas Observatory, Chile.
  3. Minker, K., Carry, B., Vachier, F., Marsset, M., Durech, J., Hanus, J., Liberato, L., Merline, W., Margot, J., Dumas, C., Close, L., Conrad, A., Grundy, W., Behrend, R., Roy, R., Berthier, J., Sokova, I., Sokov, E., Gorshanov, D., Ferrais, M., Jehin, E., Martin, A., Alton, K., 2025, A&A, 701, A42, A dynamical dichotomy in large binary asteroids
    Context. No less than 15% of large asteroids (with diameters greater than 140 km) have satellites. The commonly accepted mechanism for their formation is post-impact reaccumulation. However, the detailed physical and dynamical properties of these systems are not well understood, and many of them have not been studied in detail. Aims. We studied the population of large binary asteroid systems, in part through the characterization of (283) Emma and (762) Pulcova. To do so, we compared the gravitational fields predicted from the shape of the primary body with the non-Keplerian gravitational components identified in orbital models of the satellites of each system. We contextualize these systems in the greater population of large binary systems, thus providing clues to asteroid satellite formation. Methods. We reduced all historical high angular resolution adaptive optics (AO) images from ground-based telescopes to conduct astrometric and photometric measurements of each system's components. We then determined orbital solutions for each system using the genoid algorithm. We modeled the shapes of the system primaries using light curve-inversion techniques scaled with stellar occultations and AO images, and we developed internal structure models using SHTOOLS. Finally, we compared the distribution of the physical and orbital properties of the known binary asteroid systems. Results. We find a very low residual orbital solution for Emma with a gravitational quadrupole J2 value that is significantly lower than expected from the shape model, implying that Emma has a significantly nonhomogeneous internal structure, and an overall bulk density of 0.9 0.3 g cm-33. The circular co-planar orbit of Pulcova's satellite leaves substantial ambiguity in the orbital solution. We also find that the differences between these systems reflect an overall dichotomy within the population of large binary systems, with a strong correlation between primary elongation and satellite eccentricity observed in one group. Conclusions. We determine that there may be two distinct formation pathways influencing the end-state dichotomy in these binary systems, and that (762) Pulcova and (283) Emma belong to the two separate groups.
  4. Polanski, A., Crossfield, I., Seifahrt, A., Bean, J., Brande, J., Collins, K., Coria, D., Fukui, A., Narita, N., Sturmer, J., Giacalone, S., Kasper, D., 2025, AJ, 170, 182, An Aligned Sub-Neptune Revealed with MAROON-X and a Tendency Toward Alignment for Small Planets
    We present the RossiterMcLaughlin measurement of the sub-Neptune TOI-1759A b with MAROON-X. A joint analysis with MuSCAT3 photometry and nine additional TESS transits produces a sky-projected obliquity of = 4 18. We also derive a true obliquity of = 24 12 making this planet consistent with full alignment albeit to <1. With a period of 18.85 days and an a/R* of 40, TOI-1759A b is the longest period single sub-Neptune to have a measured obliquity. It joins a growing number of smaller planets which have had this measurement made and, along with K2-25 b, is the only single, aligned sub-Neptune known to date. We also provide an overview of the emerging distribution of obliquity measurements for planets with R < 8 R. We find that these types of planets tend toward alignment, especially the sub-Neptunes and super-Earths, implying a dynamically cool formation history. The majority of misaligned planets in this category have 4 < R 8 R and are more likely to be isolated than planets rather than in compact systems. We find this result to be significant at the 3 level, consistent with previous studies. In addition, we conduct injection and recovery testing on available archival radial velocity data to put limits on the presence of massive companions in these systems. Current archival data is insufficient for most systems to have detected a giant planet.
  5. Massey, P., Bodansky, S., Penny, L., Morrell, N., Neugent, K., 2025, ApJ, 990, 52, A New Determination of the Mass of NGC 3603-A1: The Most Massive Binary Known?
    The star NGC 3603-A1 has long been known to be a very massive binary, consisting of a pair of O2-3If*/WN5-6 stars which show WolfRayetlike emission due to their luminosities being near the Eddington limit. The system has been poorly characterized until now, due to the difficulties of obtaining reliable radial velocities from broad, blended emission lines and the extreme crowding in the cluster. However, previously unpublished archival Hubble Space Telescope (HST) Space Telescope Imaging Spectrograph (STIS) spectra revealed that some of the upper Balmer lines (seen in absorption) are well separated at favorable orbital phases, prompting us to obtain our own carefully timed new HST/STIS spectra, which we have analyzed along with the older data. Radial velocities measured from these spectra allow us to obtain an orbit for this 3.77298-day binary. We also used archival STIS imaging of the cluster to obtain a more accurate light curve for this eclipsing system, which we then modeled, yielding the orbital inclination and providing values for the stellar radii and temperatures. Together, these data show that the NGC 3603-A1 system consists of a 93.3 11.0M O3If*/WN6 primary with an effective temperature of 37,000 K, and a 70.4 9.3M O3If*/WN5 secondary that is slightly hotter, 42,000 K. Although a more massive binary is known in the LMC, NGC 3603-A1 is as massive as any binary known in our own Galaxy for which a direct measurement of its mass has been made by a fundamental method. The secondary has been spun up by mass accretion from the primary, and we discuss the evolutionary status of this intriguing system.
  6. Kroft, M., Beatty, T., Crossfield, I., Livesey, J., Becker, J., Luhn, J., Robertson, P., Bieryla, A., Ciardi, D., Clark, C., Goliguzova, M., Howell, S., Lissauer, J., Littlefield, C., Lund, M., Safonov, B., Murphy, J., Batalha, N., Bossett, M., Brande, J., Daylan, T., Dressing, C., Gagnebin, A., Huber, D., Isaacson, H., Kane, S., Kreidberg, L., Latham, D., Luque, R., Polanski, A., Premnath, P., Rhem, M., Rogers, C., Turtelboom, E., 2025, AJ, 170, 150, A Pair of Dynamically Interacting Sub-Neptunes around TOI-6054
    We confirm the planetary nature of a pair of transiting sub-Neptune exoplanets orbiting the bright F-type subgiant star TOI-6054 (V = 8.02, K = 6.673) as a part of the OrCAS radial velocity survey using WIYN/NEID observations. We find that TOI-6054b and TOI-6054c have radii of 2.64 0.15R and 2.82 0.17R, respectively, and masses of 12.5 1.7M and 9.3 1.9M. The planets have zero-albedo equilibrium temperatures of 1360 32 K and 1143 28 K. The host star has expanded and will evolve off of the main sequence within the next 500 Myr, and the resulting increase in stellar luminosity has more than doubled the stellar flux the two planets receive compared to the start of the host star's main-sequence phase. Consequently, TOI-6054b may be losing some of its primordial hydrogen/helium atmosphereif it has one. Based on dynamical simulations performed using the orbital parameters of the two planets, TOI-6054b, and TOI-6054c are very likely in a 5:3 mean motion resonance. The TOI-6054 system thus has the potential to be an excellent candidate for future atmospheric follow-up observations, with two similarly sized sub-Neptunes around a bright star. We also estimate that if TOI-6054b is currently losing its H/He atmosphere, this should be observable from space and from the ground.
  7. Barat, S., Desert, J., Mukherjee, S., Goyal, J., Xue, Q., Kawashima, Y., Vazan, A., Misener, W., Schlichting, H., Fortney, J., Bean, J., Avarsekar, S., Henry, G., Baeyens, R., Line, M., Livingston, J., David, T., Petigura, E., Sikora, J., Shivkumar, H., Feinstein, A., Oklopcic, A., 2025, AJ, 170, 165, A Metal-poor Atmosphere with a Hot Interior for a Young Sub-Neptune Progenitor: JWST/NIRSpec Transmission Spectrum of V1298 Tau b
    We present the JWST/NIRSpec G395H transmission spectrum of the young (1030 Myr) transiting planet V1298 Tau b (9.85 0.35 R, Teq = 670 K). Combined Hubble Space Telescope and JWST observations reveal a haze-free, H/He-dominated atmosphere with a large scale height (1500 km), allowing detection of CO2 (35), H2O (30), CO (10), CH4 (6), SO2 (4), and OCS (3.5). Our observations probe several scale heights (4.4 in the CO2 4.3 m band and 3 in the 2.7 m water band). The planet's mass, inferred from atmospheric scale height using free retrieval and grid modeling, is 12 1 M and 15 1.7 M, respectively, which is significantly lower than previous radial velocity estimates and confirms it as "gas-dwarf" sub-Neptune progenitor. We find an atmospheric metallicity (log Z = 0.6 0.6+0.4 solar) and subsolar C/O ratio (0.22 0.05+0.06 ). The atmospheric metallicity is low compared to mature sub-Neptunes by an order of magnitude. The CH4 abundance ([CH4] = 6.2 0.5+0.3 ]) is 7 lower than the equilibrium chemistry prediction. To adjust for the low methane abundance, the self-consistent grids favor a high internal temperature (500 K) and vertical mixing (Kzz 107108 cm2 s1). These internal temperatures are inconsistent with predictions from evolutionary models, which expect 100200 K at the current system age. We estimate a gas-to-core mass fraction between 0.1% and 8%, with a core mass of 1112 M, consistent with in-situ gas-dwarf formation. A deep atmospheric metallicity gradient may explain both the high internal temperature and low observable metallicity. Over time, mass loss from such an atmosphere could enhance its metallicity, potentially reconciling V1298 Tau b with mature sub-Neptunes.

    8. 7 publications and 2 citations in 2025.

7 publications and 2 citations total.

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