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The TESS-Keck Survey. III. A Stellar Obliquity Measurement of TOI-1726 c
Kristiansen, Martti H.; Batalha, Natalie M.; Latham, David W. +43 more
We report the measurement of a spectroscopic transit of TOI-1726c, one of two planets transiting a G-type star with V = 6.9 in the Ursa Major Moving Group (∼400 Myr). With a precise age constraint from cluster membership, TOI-1726 provides a great opportunity to test various obliquity excitation scenarios that operate on different timescales. By m…
WIYN Open Cluster Study. LXXXII. Radial-velocity Measurements and Spectroscopic Binary Orbits in the Open Cluster NGC 7789
Platais, Imants; Tofflemire, Benjamin M.; Mathieu, Robert D. +4 more
We present an extensive time-series radial-velocity (RV) survey of stars in the rich open cluster NGC 7789 (1.6 Gyr, [Fe/H] = +0.02). The stellar sample lies within an 18' circular radius from the cluster center (10 pc in projection, or about 2 core radii), and includes giants, red clump stars, blue stragglers, red stragglers, sub-subgiants, and m…
Robo-AO M-dwarf Multiplicity Survey: Catalog
Baranec, Christoph; Duev, Dmitry A.; Jensen-Clem, Rebecca +10 more
We analyze observations from Robo-AO's field M dwarf survey taken on the 2.1 m Kitt Peak telescope and perform a multiplicity comparison with Gaia DR2. Through its laser-guided, automated system, the Robo-AO instrument has yielded the largest adaptive optics M dwarf multiplicity survey to date. After developing an interface to visually identify an…
Estimating the Ultraviolet Emission of M Dwarfs with Exoplanets from Ca II and Hα
Loyd, R. O. Parke; Peacock, Sarah; Redfield, Seth +29 more
M dwarf stars are excellent candidates around which to search for exoplanets, including temperate, Earth-sized planets. To evaluate the photochemistry of the planetary atmosphere, it is essential to characterize the UV spectral energy distribution of the planet's host star. This wavelength regime is important because molecules in the planetary atm…
A Gaia Survey for Young Stars Associated with the Lupus Clouds
Luhman, K. L.
I have used high-precision photometry and astrometry from the second data release of the Gaia mission to perform a survey for young stars associated with the Lupus clouds, which have distances of ∼160 pc and reside within the Scorpius-Centaurus (Sco-Cen) OB association. The Gaia data have made it possible to distinguish Lupus members from most of …
A Highly Eccentric Warm Jupiter Orbiting TIC 237913194
Trifonov, Trifon; Henning, Thomas; Latham, David W. +28 more
The orbital parameters of warm Jupiters serve as a record of their formation history, providing constraints on formation scenarios for giant planets on close and intermediate orbits. Here, we report the discovery of TIC 237913194b, detected in full-frame images from Sectors 1 and 2 of the Transiting Exoplanet Survey Satellite (TESS), ground-based …
A Featureless Infrared Transmission Spectrum for the Super-puff Planet Kepler-79d
Deming, Drake; Madhusudhan, Nikku; Wakeford, Hannah R. +12 more
Extremely low-density planets ("super-puffs") are a small but intriguing subset of the transiting planet population. With masses in the super-Earth range (1 - 10 ${M}_{\oplus }$ ) and radii akin to those of giant planets (> 4 ${R}_{\oplus }$ ), their large envelopes may have been accreted beyond the water snow line and many appear to be suscept…
Speckle Interferometry at SOAR in 2019
Tokovinin, Andrei; Horch, Elliott P.; Mason, Brian D. +2 more
The results of speckle-interferometric observations at the 4.1 m Southern Astrophysical Research Telescope in 2019 are given, totaling 2555 measurements of 1972 resolved pairs with separations from 15 mas (median 0"21) and magnitude difference up to 6 mag, and non-resolutions of 684 targets. We resolved for the first time 90 new pairs or subsystem…
Zodiacal Exoplanets in Time (ZEIT). IX. A Flat Transmission Spectrum and a Highly Eccentric Orbit for the Young Neptune K2-25b as Revealed by Spitzer
Gaidos, Eric; Dalba, Paul A.; Rizzuto, Aaron C. +9 more
Transiting planets in nearby young clusters offer the opportunity to study the atmospheres and dynamics of planets during their formative years. To this end, we focused on K2-25b—a close-in (P = 3.48 days), Neptune-sized exoplanet orbiting a M4.5 dwarf in the 650 Myr Hyades cluster. We combined photometric observations of K2-25 covering a total of…
H- and Dissociation in Ultra-hot Jupiters: A Retrieval Case Study of WASP-18b
Madhusudhan, Nikku; Gandhi, Siddharth; Mandell, Avi
Atmospheres of a number of ultra-hot Jupiters (UHJs) with temperatures ≳2000 K have been observed recently. Many of these planets show largely featureless thermal spectra in the near-infrared observed with the HST WFC3 spectrograph (1.1-1.7 µm) even though this spectral range contains strong H2O opacity. Recent works have proposed…