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Two Massive Jupiters in Eccentric Orbits from the TESS Full-frame Images
Butler, R. Paul; Vanderburg, Andrew; Bieryla, Allyson +43 more
We report the discovery of two short-period massive giant planets from NASA's Transiting Exoplanet Survey Satellite (TESS). Both systems, TOI-558 (TIC 207110080) and TOI-559 (TIC 209459275), were identified from the 30 minute cadence full-frame images and confirmed using ground-based photometric and spectroscopic follow-up observations from TESS's…
The LHS 1678 System: Two Earth-sized Transiting Planets and an Astrometric Companion Orbiting an M Dwarf Near the Convective Boundary at 20 pc
Kostov, Veselin B.; Torres, Guillermo; Barclay, Thomas +48 more
We present the Transiting Exoplanet Survey Satellite (TESS) discovery of the LHS 1678 (TOI-696) exoplanet system, comprised of two approximately Earth-sized transiting planets and a likely astrometric brown dwarf orbiting a bright (V J = 12.5, K s = 8.3) M2 dwarf at 19.9 pc. The two TESS-detected planets are of radius 0.7…
Spectroscopic Orbits of Subsystems in Multiple Stars. VIII.
Tokovinin, Andrei
Periods, eccentricities, and masses in hierarchical stellar systems inform us on the formation and early evolution of these fascinating objects. To complement the multiplicity statistics of nearby solar-type stars, 19 new spectroscopic orbits of inner subsystems in 15 hierarchies (10 triples and 5 quadruples) are determined based on high-resolutio…
The POKEMON Speckle Survey of Nearby M Dwarfs. I. New Discoveries
Kiman, Rocio; Ciardi, David R.; Clark, Catherine A. +4 more
M dwarfs are favorable targets for exoplanet detection with current instrumentation, but stellar companions can induce false positives and inhibit planet characterization. Knowledge of stellar companions is also critical to our understanding of how binary stars form and evolve. We have therefore conducted a survey of stellar companions around near…
Mapping the Pressure-dependent Day-Night Temperature Contrast of a Strongly Irradiated Atmosphere with HST Spectroscopic Phase Curve
Mayorga, L. C.; Apai, Dániel; Marley, Mark +6 more
Many brown dwarfs are on ultrashort-period and tidally locked orbits around white dwarf hosts. Because of these small orbital separations, the brown dwarfs are irradiated at levels similar to hot Jupiters. Yet, they are easier to observe than hot Jupiters because white dwarfs are fainter than main-sequence stars at near-infrared wavelengths. Irrad…
Prediction of Astrometric-microlensing Events from Gaia eDR3 Proper Motions
Bastian, Ulrich; Wambsganss, Joachim; Klüter, Jonas +1 more
Astrometric microlensing is a unique tool to measure stellar masses. It allows us to determine the mass of the lensing star with an accuracy of a few percent. In this paper, we update, extend, and refine our predictions of astrometric-microlensing events based on Gaia's early Data release 3 (eDR3). We selected about 500.000 high-proper-motion star…
The Chemical Composition of Extreme-velocity Stars
Hawkins, Keith; Frebel, Anna; Ji, Alexander P. +5 more
Little is known about the origin of the fastest stars in the Galaxy. Our understanding of the chemical evolution history of the Milky Way and surrounding dwarf galaxies allows us to use the chemical composition of a star to investigate its origin and to say whether it was formed in situ or was accreted. However, the fastest stars, the hypervelocit…
A Mass-Magnitude Relation for Low-mass Stars Based on Dynamical Measurements of Thousands of Binary Star Systems
Blake, Cullen H.; Giovinazzi, Mark R.
Stellar mass is a fundamental parameter that is key to our understanding of stellar formation and evolution, as well as the characterization of nearby exoplanet companions. Historically, stellar masses have been derived from long-term observations of visual or spectroscopic binary star systems. While advances in high-resolution imaging have enable…
Magnetic Activity on Four Short-period Contact Binaries: V0576 Peg, KW Psc, V0873 Per, and FY Boo
Wang, Shuang; Yang, Yuangui; Yuan, Huiyu +1 more
We presented new photometry for four short-period late-type binaries, observed by three small telescopes in China from 2020 September to 2021 December. Seven sets of light curves (including the TESS data for FY Boo) were analyzed by using the W-D method. Three binaries (V0576 Peg, V0873 Per, and FY Boo) are W-type binaries with q ≃ 2.5, while KW P…
Activity and Rotation of Nearby Field M Dwarfs in the TESS Southern Continuous Viewing Zone
Rampalli, Rayna; Mann, Andrew W.; Agüeros, Marcel A. +8 more
The evolution of magnetism in late-type dwarfs remains murky, as we can only weakly predict levels of activity for M dwarfs of a given mass and age. We report results from our spectroscopic survey of M dwarfs in the Southern Continuous Viewing Zone (CVZ) of the Transiting Exoplanet Survey Satellite (TESS). As the TESS CVZs overlap with those of th…