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The Peculiar Chemical Pattern of the WASP-160 Binary System: Signatures of Planetary Formation and Evolution?
Buccino, Andrea P.; Martioli, Eder; Mašek, Martin +8 more
Wide binary stars with similar components hosting planets provide a favorable opportunity for exploring the star-planet chemical connection. We perform a detailed characterization of the solar-type stars in the WASP-160 binary system. No planet has been reported yet around WASP-160A, while WASP-160B is known to host a transiting Saturn-mass planet…
Even More Rapidly Rotating Pre-main-sequence M Dwarfs with Highly Structured Light Curves: An Initial Survey in the Lower Centaurus-Crux and Upper Centaurus-Lupus Associations
Powell, Brian P.; Kruse, Ethan; Cody, Ann Marie +6 more
Using K2, we recently discovered a new type of periodic photometric variability while analyzing the light curves of members of Upper Sco. The 23 exemplars of this new variability type are all mid-M dwarfs, with short rotation periods. Their phased light curves have one or more broad flux dips or multiple arcuate structures which are not explicable…
Vertical Structure of Galactic Disk Kinematics from LAMOST K Giants
Zhao, Gang; Zhu, Zi; Yang, Chengqun +3 more
We examine the vertical structure of Galactic disk kinematics over a Galactocentric radial distance range of R = 5-15 kpc and up to 3 kpc away from the Galactic plane, using the K-type giants surveyed by LAMOST. Based on robust measurements of three-dimensional velocity moments, a wobbly disk is detected in a phenomenological sense. An outflow dom…
The Pre-He White Dwarfs in Eclipsing Binaries. II. WASP 0843-11
Koo, Jae-Rim; Han, Cheongho; Hong, Kyeongsoo +5 more
We present the Transiting Exoplanet Survey Satellite (TESS) photometry and our high-resolution spectra of the EL CVn-type star 1SWASP J084356.46-113327.5 (WASP 0843-11), which consists of an F-type main-sequence (MS) star and a hotter low-mass helium white dwarf precursor (pre-He WD). In a spectral analysis, double-lined radial velocities (RVs) we…
Resolving the Circumstellar Environment of the Galactic B[e] Supergiant Star MWC 137.II. Nebular Kinematics and Stellar Variability
Liimets, Tiina; Kraus, Michaela; Jones, David +4 more
The Galactic B[e] supergiant MWC 137 is surrounded by a large-scale optical nebula. To shed light on the physical conditions and kinematics of the nebula, we analyze the optical forbidden emission lines [N II] λλ 6548,6583 and [S II] λλ 6716,6731 in long-slit spectra taken with ALFOSC at the Nordic Optical Telescope. The radial velocities display …
The Initial-Final Mass Relation for Hydrogen-deficient White Dwarfs
Bolte, Michael; Williams, Kurtis A.; Barnett, Joseph W. +1 more
The initial-final mass relation represents the total mass lost by a star during the entirety of its evolution from the zero age main sequence to the white-dwarf cooling track. The semiempirical initial-final mass relation (IFMR) is largely based on observations of DA white dwarfs, the most common spectral type of white dwarf and the simplest atmos…
Wolf 503 b: Characterization of a Sub-Neptune Orbiting a Metal-poor K Dwarf
Butler, R. Paul; Gorjian, Varoujan; López-Morales, Mercedes +35 more
Using radial-velocity measurements from four instruments, we report the mass and density of a 2.043 ±0.069 R ⊕ sub-Neptune orbiting the quiet K-dwarf Wolf 503 (HIP 67285). In addition, we present improved orbital and transit parameters by analyzing previously unused short-cadence K2 campaign 17 photometry and conduct a joint radial-velo…
Bayesian Cross-matching of High Proper-motion Stars in Gaia DR2 and Photometric Metallicities for 1.7 million K and M Dwarfs
Lépine, Sébastien; Medan, Ilija; Hartman, Zachary
We present a Bayesian method to cross-match 5,827,988 high proper-motion Gaia sources ( > 40 mas yr1) to various photometric surveys: Two Micron All Sky Survey, AllWISE data release from the Wide-field Infrared Explorer (WISE) mission, Galaxy Evolution Explorer, Radial Velocity Experiment, Sloan Digital Sky Survey, and Panoramic Surv…
Multiband Imaging of the HD 36546 Debris Disk: A Refined View from SCExAO/CHARIS
Henning, Thomas; Currie, Thayne; Kwon, Jungmi +21 more
We present the first multiwavelength (near-infrared; 1.1-2.4 µm) imaging of HD 36546's debris disk, using the Subaru Coronagraphic Extreme Adaptive Optics (SCExAO) system coupled with the Coronagraphic High Angular Resolution Imaging Spectrograph (CHARIS). As a 3-10 Myr old star, HD 36546 presents a rare opportunity to study a debris disk at…
The Rise and Fall of the Eclipsing Binary HS Hydrae
Davenport, James. R. A.; Windemuth, Diana; Warmbein, Karen +3 more
HS Hydrae is a short period eclipsing binary (Porb = 1.57 day) that belongs to a rare group of systems observed to have rapidly changing inclinations. This evolution is due to a third star on an intermediate orbit, and results in significant differences in eclipse depths and timings year to year. Zasche & Paschke revealed that HS Hy…