Search Publications
A Fourth Planet in the Kepler-51 System Revealed by Transit Timing Variations
Fu, Guangwei; Stevenson, Kevin B.; Bieryla, Allyson +49 more
Kepler-51 is a ≲1 Gyr old Sun-like star hosting three transiting planets with radii ≈6–9 R ⊕ and orbital periods ≈45–130 days. Transit timing variations (TTVs) measured with past Kepler and Hubble Space Telescope (HST) observations have been successfully modeled by considering gravitational interactions between the three transiting plan…
TOI-2015 b: A Warm Neptune with Transit Timing Variations Orbiting an Active Mid-type M Dwarf
Kobulnicky, Henry A.; Hawley, Suzanne L.; Cochran, William D. +29 more
We report the discovery of a close-in (P orb = 3.349 days) warm Neptune with clear transit timing variations (TTVs) orbiting the nearby (d = 47.3 pc) active M4 star, TOI-2015. We characterize the planet's properties using Transiting Exoplanet Survey Satellite (TESS) photometry, precise near-infrared radial velocities (RVs) with the Habi…
JWST-TST High Contrast: Spectroscopic Characterization of the Benchmark Brown Dwarf HD 19467 B with the NIRSpec Integral Field Spectrograph
van der Marel, Roeland P.; Perrin, Marshall D.; Pueyo, Laurent +14 more
We present the atmospheric characterization of the substellar companion HD 19467 B as part of the pioneering James Webb Space Telescope Guaranteed Time Observer program to obtain moderate resolution spectra (R ∼ 2700, 3–5 µm) of a high-contrast companion with the NIRSpec integral field unit (IFU). HD 19467 B is an old, ∼9 Gyr, companion to a…
Asteroid Orbit Determination Using Gaia FPR: Statistical Analysis
Naidu, Shantanu P.; Farnocchia, Davide; Park, Ryan S. +1 more
The Gaia mission has provided astrometric observations of unprecedented accuracy for more than 156,000 asteroids. The reported astrometric uncertainties are of the order of milliarcseconds, about 2 orders of magnitude smaller than that of traditional ground-based observations. The accuracy of Gaia data requires a high-fidelity orbit determination …
How Well is the International Celestial Reference System Maintained in Official IAU Implementations?
Malkin, Zinovy
The International Celestial Reference Frame (ICRF) based on the VLBI-derived positions of 608 extragalactic radio sources was adopted by the International Astronomical Union (IAU) in 1998 as the first realization of the International Celestial Reference System (ICRS). Later, in 2009 and 2020, two extended ICRF versions, ICRF2 and ICRF3, respective…
Analyzing JWST/NIRSpec Hydrogen Line Detections at TWA 27B: Constraining Accretion Properties and Geometry
Hashimoto, Jun; Marleau, Gabriel-Dominique; Aoyama, Yuhiko
Hydrogen lines from forming planets are crucial for understanding planet formation. However, the number of planetary hydrogen line detections is still limited. Recent JWST/NIRSpec observations have detected Paschen and Brackett hydrogen lines at TWA 27 B (2M1207b). Although classified as a planetary- mass companison (PMC) rather than a planet due …
The TESS-Keck Survey. VII. A Superdense Sub-Neptune Orbiting TOI-1824
Batalha, Natalie M.; Mayo, Andrew W.; Rice, Malena +35 more
We confirm a massive sub-Neptune-sized planet on a P = 22.8 days orbit around the star TOI-1824 (T eff = 5200 K, V = 9.7 mag). TESS first identified TOI-1824 b (formerly TOI-1824.01) as an object of interest in 2020 April after two transits in Sector 22 were matched with a single transit in Sector 21. TOI-1824 was subsequently targeted …
TESS Hunt for Young and Maturing Exoplanets (THYME). X. A Two-planet System in the 210 Myr MELANGE-5 Association
Vanderburg, Andrew; Triaud, Amaury H. M. J.; Quinn, Samuel N. +35 more
Young (<500 Myr) planets are critical to studying how planets form and evolve. Among these young planetary systems, multiplanet configurations are particularly useful, as they provide a means to control for variables within a system. Here, we report the discovery and characterization of a young planetary system, TOI-1224. We show that the plane…
ABYSS. II. Identification of Young Stars in Optical SDSS Spectra and Their Properties
Stassun, Keivan G.; Kounkel, Marina; Hillenbrand, Lynne A. +9 more
We developed a tool that measures equivalent widths of various lines in low-resolution optical spectra, and it was applied to stellar spectra obtained as part of SDSS-V and LAMOST programs. These lines, such as Li I, which directly indicates stellar youth, or optical H I and Ca II, which in emission indicate activity associated with stellar youth,…
Atmospheric Characterization of the Super-Jupiter HIP 99770 b with KPIC
Zhang, Yapeng; Do Ó, Clarissa R.; Fitzgerald, Michael P. +28 more
Young, self-luminous super-Jovian companions discovered by direct imaging provide a challenging test for planet formation and evolution theories. By spectroscopically characterizing the atmospheric compositions of these super-Jupiters, we can constrain their formation histories. Here we present studies of the recently discovered HIP 99770 b, a 16 …