Search Publications
A Mirage or an Oasis? Water Vapor in the Atmosphere of the Warm Neptune TOI-674 b
Fortney, Jonathan J.; Mikal-Evans, Thomas; Lothringer, Joshua D. +14 more
We report observations of the recently discovered warm Neptune TOI-674 b (5.25 R ⊕, 23.6 M ⊕) with the Hubble Space Telescope's Wide Field Camera 3 instrument. TOI-674 b is in the Neptune desert, an observed paucity of Neptune-size exoplanets at short orbital periods. Planets in the desert are thought to have complex evolutio…
Kepler-1656b's Extreme Eccentricity: Signature of a Gentle Giant
Howard, Andrew W.; Angelo, Isabel; Naoz, Smadar +4 more
Highly eccentric orbits are one of the major surprises of exoplanets relative to the solar system and indicate rich and tumultuous dynamical histories. One system of particular interest is Kepler-1656, which hosts a sub-Jovian planet with an eccentricity of 0.8. Sufficiently eccentric orbits will shrink in the semimajor axis due to tidal dissipati…
Moderate-resolution K-band Spectroscopy of the Substellar Companion VHS 1256 b
Macintosh, Bruce; Perrin, Marshall D.; Barman, Travis S. +6 more
We present moderate-resolution (R ~ 4000) K-band spectra of the planetary-mass companion VHS 1256 b. The data were taken with the OSIRIS integral field spectrograph at the W.M. Keck Observatory. The spectra reveal resolved molecular lines from H2O and CO. The spectra are compared to custom PHOENIX atmosphere model grids appropriate for …
The Rapid Rotation of the Strongly Magnetic Ultramassive White Dwarf EGGR 156
Hermes, J. J.; Vanderbosch, Zachary P.; Williams, Kurtis A.
The distribution of white dwarf rotation periods provides a means for constraining angular momentum evolution during the late stages of stellar evolution, as well as insight into the physics and remnants of double degenerate mergers. Although the rotational distribution of low-mass white dwarfs is relatively well constrained via asteroseismology, …
HD-TESS: An Asteroseismic Catalog of Bright Red Giants within TESS Continuous Viewing Zones
Huber, Daniel; Stello, Dennis; Hon, Marc +2 more
We present HD-TESS, a catalog of 1709 bright (V ~ 3-10) red giants from the Henry Draper (HD) Catalog with asteroseismic measurements based on photometry from NASA's Transiting Exoplanet Survey Satellite (TESS). Using light curves spanning at least 6 months across a single TESS observing cycle, we provide measurements of global asteroseismic param…
The Triangulum Extended (TREX) Survey: The Stellar Disk Dynamics of M33 as a Function of Stellar Age
Williams, Benjamin F.; Gilbert, Karoline M.; Chemin, Laurent +8 more
Triangulum (M33) is a low-mass, relatively undisturbed spiral galaxy that offers a new regime in which to test models of dynamical heating. In spite of its proximity, M33's dynamical heating history has not yet been well-constrained. In this work, we present the TREX Survey, the largest stellar spectroscopic survey across the disk of M33. We prese…
Detection of Near-infrared Water Ice at the Surface of the (Pre)Transitional Disk of AB Aur: Informing Icy Grain Abundance, Composition, and Size
Pinte, C.; Ménard, F.; Duchêne, G. +17 more
We present near-infrared Large Binocular Telescope LMIRCam imagery of the disk around the Herbig Ae/Be star AB Aurigae. A comparison of the surface brightness at K s (2.16 µm), H2O narrowband (3.08 µm), and $L^{\prime} $ (3.7 µm) allows us to probe the presence of icy grains in this (pre)transitional disk …
Automatic Morphological Classification of Galaxies: Convolutional Autoencoder and Bagging-based Multiclustering Model
Fang, Guanwen; Lin, Zesen; Gu, Yizhou +1 more
In order to obtain morphological information of unlabeled galaxies, we present an unsupervised machine-learning (UML) method for morphological classification of galaxies, which can be summarized as two aspects: (1) the methodology of convolutional autoencoder (CAE) is used to reduce the dimensions and extract features from the imaging data; (2) th…
Correcting Stellar Flare Frequency Distributions Detected by TESS and Kepler
Yang, Ming; Zhou, Ji-Lin; Liu, Hui-Gen +1 more
The habitability of planets is closely connected with stellar activity, mainly the frequency of flares and the distribution of flare energy. Kepler and TESS find many flaring stars via precise time-domain photometric data, and the frequency and energy distribution of stellar flares on different types of stars are studied statistically. However, th…
A Dearth of Close-in Stellar Companions to M-dwarf TESS Objects of Interest
Howell, Steve B.; Beichman, Charles A.; Ciardi, David R. +5 more
TESS has proven to be a powerful resource for finding planets, including those that orbit the most prevalent stars in our galaxy: M dwarfs. Identification of stellar companions (both bound and unbound) has become a standard component of the transiting planet confirmation process in order to assess the level of light-curve dilution and the possibil…