*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/

If you notice publications that are missing, or ones that do not belong, please let us know (send email to sel .at. lowell .dot. edu).

For missing articles, please send either the ADS bibcode, or a standard short form journal citation.

Authors affiliated with "Lowell Obs" are highlighted.

Return to Lowell Annual Summaries

2025

1. Corbett, T., Doner, A., Horanyi, M., Brandt, P., Grundy, W., Lisse, C., Parker, J., Peltier, L., Poppe, A., Singer, K., Stern, S., Verbiscer, A., 2025, ApJL, 979, L50, Production, Transport, and Destruction of Dust in the Kuiper Belt: The Effects of Refractory and Volatile Grain Compositions
   Abstract

   The Venetia Burney Student Dust Counter (SDC) on board the New Horizons spacecraft measures the spatial and size distributions of dust along its trajectory. Models based on early SDC measurements predicted a peak dust number density at a heliocentric distance of 40 au, followed by a rapid decline. Instead, SDC observed dust fluxes 23 times higher than predicted between 40 and 60 au. One potential explanation for this discrepancy is that SDC may be encountering icy grains with different dynamical behavior than previously modeled silicate grains. Due to ultraviolet photosputtering, waterice grains rapidly erode and migrate outward, significantly contributing to the measured dust number densities only at distances 40 au. We present a model of silicate and ice grain dynamics in the outer solar system, considering gravitational and radiation forces and grain erosion. Using SDC data, we estimate that the mass production rate of ice grains between 0.1 and 10 m in the Kuiper Belt (KB) would need to be 2070 times higher than that of silicate grains. However, KB grains are expected to be refractory/volatile mixtures rather than pure silicate or ice. Thus, we briefly explore simple models of more realistic mixed-grain cases to further gauge the effects of grain composition on the equilibrium dust distribution. Future SDC measurements at greater distances will test the model predictions and further constrain silicate and ice grain production rates in the KB.

2. Crossfield, I., Polanski, A., Robertson, P., Murphy, J., Turtelboom, E., Luque, R., Beatty, T., Daylan, T., Isaacson, H., Brande, J., Kreidberg, L., Batalha, N., Huber, D., Rhem, M., Dressing, C., Kane, S., Bossett, M., Gagnebin, A., Kroft, M., Premnath, P., Rogers, C., Collins, K., Latham, D., Watkins, C., Ciardi, D., Howell, S., Savel, A., Berlind, P., Calkins, M., Esquerdo, G., Mink, J., Clark, C., Lund, M., Matson, R., Everett, M., Schlieder, J., Matthews, E., Giacalone, S., Barclay, T., Zambelli, R., Plavchan, P., Ellingson, T., Bowen, M., Srdoc, G., McLeod, K., Schwarz, R., Barkaoui, K., Kamler, J., Murgas, F., Palle, E., Narita, N., Fukui, A., Relles, H., Bieryla, A., Girardin, E., Massey, B., Stockdale, C., Lewin, P., Papini, R., Guerra, P., Conti, D., Yalcinkaya, S., Basturk, O., Mourad, G., 2025, AJ, 169, 89, OrCAS: Origins, Compositions, and Atmospheres of Sub-Neptunes. I. Survey Definition
   Abstract

   Sub-Neptunesvolatile-rich exoplanets smaller than Neptuneare intrinsically the most common type of planet known. However, the formation and nature of these objects, as well as the distinctions between subclasses (if any), remain unclear. Two powerful tools to tease out the secrets of these worlds are measurements of (i) atmospheric composition and structure revealed by transit and/or eclipse spectroscopy, and (ii) mass, radius, and density revealed by transit photometry and Doppler spectroscopy. Here, we present OrCAS, a survey to better elucidate the origins, compositions, and atmospheres of sub-Neptunes. This radial velocity survey uses a repeatable, quantifiable metric to select targets suitable for subsequent transmission spectroscopy and address key science themes about the atmospheric and internal compositions and architectures of these systems. Our survey targets 26 systems with transiting sub-Neptune planet candidates, with the overarching goal of increasing the sample of such planets suitable for subsequent atmospheric characterization. This paper lays out our survey's science goals, defines our target prioritization metric, and performs light-curve fits and statistical validation using existing TESS photometry and ground-based follow-up observations. Our survey serves to continue expanding the sample of small exoplanets with well-measured properties orbiting nearby bright stars, ensuring fruitful studies of these systems for many years to come.

2 publications and 0 citations in 2025.

2 publications and 0 citations total.