Search Publications
The ASAS-SN catalogue of variable stars VI: an all-sky sample of δ Scuti stars
Kochanek, C. S.; Stanek, K. Z.; Thompson, Todd A. +10 more
We characterize an all-sky catalogue of ∼8400 δ Scuti variables in ASAS-SN, which includes ∼3300 new discoveries. Using distances from Gaia DR2, we derive period-luminosity relationships for both the fundamental mode and overtone pulsators in the WJK, V, Gaia DR2 G, J, H, Ks, and W1 bands. We find that the overtone…
Two Intermediate-mass Transiting Brown Dwarfs from the TESS Mission
Henning, Thomas; Hellier, Coel; Latham, David W. +28 more
We report the discovery of two intermediate-mass transiting brown dwarfs (BDs), TOI-569b and TOI-1406b, from NASA's Transiting Exoplanet Survey Satellite mission. TOI-569b has an orbital period of P = 6.55604 ± 0.00016 days, a mass of Mb = 64.1 ± 1.9 ${M}_{{\rm{J}}}$ , and a radius of Rb = 0.75 ± 0.02 ${R}_{{\rm{J}}}$ . Its h…
Detailed Abundances in the Ultra-faint Magellanic Satellites Carina II and III
Bechtol, K.; Allam, S.; Gruendl, R. A. +14 more
We present the first detailed elemental abundances in the ultra-faint Magellanic satellite galaxies Carina II (Car II) and Carina III (Car III). With high-resolution Magellan/MIKE spectroscopy, we determined the abundances of nine stars in Car II, including the first abundances of an RR Lyrae star in an ultra-faint dwarf galaxy (UFD), and two star…
Runaway and walkaway stars from the ONC with Gaia DR2
Parker, Richard J.; Schoettler, Christina; de Bruijne, Jos +1 more
Theory predicts that we should find fast, ejected (runaway) stars of all masses around dense, young star-forming regions. N-body simulations show that the number and distribution of these ejected stars could be used to constrain the initial spatial and kinematic substructure of the regions. We search for runaway and slower walkaway stars within 10…
The MOSDEF Survey: Kinematic and Structural Evolution of Star-forming Galaxies at 1.4 ≤ z ≤ 3.8
Barro, Guillermo; Übler, Hannah; Siana, Brian +15 more
We present ionized gas kinematics for 681 galaxies at $z\sim 1.4\mbox{--}3.8$ from the MOSFIRE Deep Evolution Field survey, measured using models that account for random galaxy-slit misalignments together with structural parameters derived from CANDELS Hubble Space Telescope (HST) imaging. Kinematics and sizes are used to derive dynamical masses. …
Updated Parameters and a New Transmission Spectrum of HD 97658b
Mikal-Evans, Thomas; Henry, Gregory W.; Knutson, Heather A. +23 more
Recent years have seen increasing interest in the characterization of sub-Neptune-sized planets because of their prevalence in the Galaxy, contrasted with their absence in our solar system. HD 97658 is one of the brightest stars hosting a planet of this kind, and we present the transmission spectrum of this planet by combining four Hubble Space Te…
Weighing in on black hole binaries with BPASS: LB-1 does not contain a 70 M⊙ black hole
Steeghs, D. T. H.; Stanway, E. R.; Eldridge, J. J. +3 more
The recent identification of a candidate very massive (70 M⊙) black hole (BH) is at odds with our current understanding of stellar winds and pair-instability supernovae. We investigate alternate explanations for this system by searching the BPASS v2.2 stellar and population synthesis models for those that match the observed properties o…
A Terrestrial-mass Rogue Planet Candidate Detected in the Shortest-timescale Microlensing Event
Han, Cheongho; Udalski, Andrzej; Lee, Chung-Uk +29 more
Some low-mass planets are expected to be ejected from their parent planetary systems during early stages of planetary system formation. According to planet formation theories, such as the core accretion theory, typical masses of ejected planets should be between 0.3 and 1.0 M⊕. Although in practice such objects do not emit any light, th…
The tidal remnant of an unusually metal-poor globular cluster
Lewis, Geraint F.; Casey, Andrew R.; Erkal, Denis +18 more
Globular clusters are some of the oldest bound stellar structures observed in the Universe1. They are ubiquitous in large galaxies and are believed to trace intense star-formation events and the hierarchical build-up of structure2,3. Observations of globular clusters in the Milky Way, and a wide variety of other galaxies, hav…
The Bulge Radial Velocity Assay for RR Lyrae Stars (BRAVA-RR) DR2: A Bimodal Bulge?
Rich, R. Michael; Kunder, Andrea; Wojno, Jennifer +11 more
The radial velocities of 2768 fundamental-mode RR Lyrae stars (RRLs) toward the southern Galactic bulge are presented, spanning the southern bulge from -8° < l < + 8° and -3° < b < -6°. Distances derived from the pulsation properties of the RRLs are combined with Gaia proper motions to give constraints on the orbital motions of 1389 RR…