Search Publications
Three Small Planets Transiting a Hyades Star
Cochran, William D.; Endl, Michael; Tamura, Motohide +33 more
We present the discovery of three small planets transiting K2-136 (LP 358 348, EPIC 247589423), a late K dwarf in the Hyades. The planets have orbital periods of 7.9757 ± 0.0011, {17.30681}-0.00036+0.00034, and {25.5715}-0.0040+0.0038 {days}, and radii of 1.05 ± 0.16, 3.14 ± 0.36, and {1.55}-0.21
Limits on Clouds and Hazes for the TRAPPIST-1 Planets
Moran, Sarah E.; Batalha, Natasha E.; Wakeford, Hannah R. +2 more
The TRAPPIST-1 planetary system is an excellent candidate for study of the evolution and habitability of M-dwarf-hosted planets. Transmission spectroscopy observations performed on the system with the Hubble Space Telescope (HST) suggest that the innermost five planets do not possess clear hydrogen atmospheres. Here we reassess these conclusions w…
Orbit and Dynamical Mass of the Late-T Dwarf GL 758 B
Cochran, William D.; Endl, Michael; Wittenmyer, Robert A. +11 more
Gl 758 B is a late-T dwarf orbiting a metal-rich Sun-like star at a projected separation of ρ ≈ 1.″6 (25 au). We present four epochs of astrometry of this system with NIRC2 at Keck Observatory spanning 2010 to 2017 together with 630 radial velocities (RVs) of the host star acquired over the past two decades from McDonald Observatory, Keck Observat…
Discovery and Dynamical Analysis of an Extreme Trans-Neptunian Object with a High Orbital Inclination
Smith, M.; D'Andrea, C. B.; Abdalla, F. B. +63 more
We report the discovery and dynamical analysis of 2015 BP519, an extreme trans-Neptunian object (TNO) detected by the Dark Energy Survey at a heliocentric distance of 55 au, perihelion of ∼36 au, and absolute magnitude H r = 4.3. The current orbit, determined from a 1110 day observational arc, has a semimajor axis a ≈ 450 a…
KELT-19Ab: A P ∼ 4.6-day Hot Jupiter Transiting a Likely Am Star with a Distant Stellar Companion
Bieryla, Allyson; Latham, David W.; Quinn, Samuel N. +51 more
We present the discovery of the giant planet KELT-19Ab, which transits the moderately bright (V∼ 9.9) A8V star TYC 764-1494-1 with an orbital period of 4.61 days. We confirm the planetary nature of the companion via a combination of radial velocities, which limit the mass to ≲ 4.1 {M}{{J}} (3σ ), and a clear Doppler tomography signal, w…
Zodiacal Exoplanets in Time (ZEIT). VII. A Temperate Candidate Super-Earth in the Hyades Cluster
Vanderburg, Andrew; Bieryla, Allyson; Latham, David W. +15 more
Transiting exoplanets in young open clusters present opportunities to study how exoplanets evolve over their lifetimes. Recently, significant progress detecting transiting planets in young open clusters has been made with the K2 mission, but so far all of these transiting cluster planets orbit close to their host stars, so planet evolution can onl…
A Compact Multi-planet System with a Significantly Misaligned Ultra Short Period Planet
Kristiansen, Martti H.; Omohundro, Mark; Vanderburg, Andrew +20 more
We report the discovery of a compact multi-planet system orbiting the relatively nearby (78 pc) and bright (K = 8.9) K-star, K2-266 (EPIC 248435473). We identify up to six possible planets orbiting K2-266 with estimated periods of P b = 0.66, P .02 = 6.1, P c = 7.8, P d = 14.7, P e = 1…
A New Catalog of Radial Velocity Standard Stars from the APOGEE Data
Huang, Y.; Chen, B. -Q.; Wang, C. +5 more
We present a new catalog of 18080 radial velocity (RV) standard stars selected from the APOGEE data. These RV standard stars are observed at least three times and have a median stability (3σ RV) around 240 m s-1 over a time baseline longer than 200 days. They are largely distributed in the northern sky and could be extended t…
New Young Stars and Brown Dwarfs in the Upper Scorpius Association
Luhman, K. L.; Esplin, T. L.; Mamajek, E. E. +2 more
To improve the census of the Upper Sco association (∼11 Myr, ∼145 pc), we have identified candidate members using parallaxes, proper motions, and color-magnitude diagrams from several wide-field imaging surveys and have obtained optical and infrared spectra of several hundred candidates to measure their spectral types and assess their membership. …
A WISE Survey of Circumstellar Disks in the Upper Scorpius Association
Luhman, K. L.; Esplin, T. L.; Mamajek, E. E. +1 more
We have performed a survey for new members of the Upper Sco association that have circumstellar disks using mid-infrared photometry from the Wide-field Infrared Survey Explorer (WISE). Through optical and near-infrared spectroscopy, we have confirmed 185 candidates as likely members of Upper Sco with spectral types ranging from mid-K to M9. They c…