Search Publications
A Volume-limited Sample of Ultracool Dwarfs. I. Construction, Space Density, and a Gap in the L/T Transition
Magnier, Eugene A.; Dupuy, Trent J.; Liu, Michael C. +1 more
We present a new volume-limited sample of L0-T8 dwarfs out to 25 pc defined entirely by parallaxes, using our recent measurements from UKIRT/WFCAM along with Gaia DR2 and literature parallaxes. With 369 members, our sample is the largest parallax-defined volume-limited sample of L and T dwarfs to date, yielding the most precise space densities for…
The Detection and Characterization of Be+sdO Binaries from HST/STIS FUV Spectroscopy
Gies, Douglas R.; Lester, Kathryn V.; Wang, Luqian +4 more
The B emission-line stars are rapid rotators that were probably spun up by mass and angular momentum accretion through mass transfer in an interacting binary. Mass transfer will strip the donor star of its envelope to create a small and hot subdwarf remnant. Here we report on Hubble Space Telescope/STIS far-ultraviolet spectroscopy of a sample of …
Final Targeting Strategy for the Sloan Digital Sky Survey IV Apache Point Observatory Galactic Evolution Experiment 2 North Survey
Cohen, Roger E.; Bizyaev, Dmitry; Bovy, Jo +58 more
The Apache Point Observatory Galactic Evolution Experiment 2 (APOGEE-2) is a dual-hemisphere, near-infrared (NIR), spectroscopic survey with the goal of producing a chemodynamical mapping of the Milky Way. The targeting for APOGEE-2 is complex and has evolved with time. In this paper, we present the updates and additions to the initial targeting s…
Gaia EDR3 Reveals the Substructure and Complicated Star Formation History of the Greater Taurus-Auriga Star-forming Complex
Rizzuto, Aaron C.; Kraus, Adam L.; Krolikowski, Daniel M.
The Taurus-Auriga complex is the prototypical low-mass star-forming region, and provides a unique testbed of the star formation process, which left observable imprints on the spatial, kinematic, and temporal structure of its stellar population. Taurus's rich observational history has uncovered peculiarities that suggest a complicated star-forming …
The Extragalactic Distance Database: The Color-Magnitude Diagrams/Tip of the Red Giant Branch Distance Catalog
Dolphin, Andrew E.; Wu, Po-Feng; Anand, Gagandeep S. +7 more
The Extragalactic Distance Database (EDD) was created as a repository for high-quality, redshift-independent distances. A key component of EDD is the Color-Magnitude Diagrams/Tip of the Red Giant Branch (CMDs/TRGB) catalog, which provides information on the stellar content of nearby galaxies observed with the Hubble Space Telescope (HST). Here we …
Validation of the Gaia Early Data Release 3 Parallax Zero-point Model with Asteroseismology
Zinn, Joel C.
Gaia Early Data Release 3 (EDR3) provides trigonometric parallaxes for 1.5 billion stars, with reduced systematics compared to Gaia Data Release 2 and reported precisions better by up to a factor of 2. New to EDR3 is a tentative model for correcting the parallaxes of magnitude-, position-, and color-dependent systematics for five- and six-paramete…
Final Targeting Strategy for the SDSS-IV APOGEE-2S Survey
Monachesi, Antonela; Drout, Maria R.; Kollmeier, Juna A. +43 more
APOGEE is a high-resolution (R ~ 22,000), near-infrared, multi-epoch, spectroscopic survey of the Milky Way. The second generation of the APOGEE project, APOGEE-2, includes an expansion of the survey to the Southern Hemisphere called APOGEE-2S. This expansion enabled APOGEE to perform a fully panoramic mapping of all of the main regions of the Mil…
Hubble WFC3 Spectroscopy of the Habitable-zone Super-Earth LHS 1140 b
Changeat, Quentin; Mori, Mayuko; Edwards, Billy +7 more
Atmospheric characterization of temperate, rocky planets is the holy grail of exoplanet studies. These worlds are at the limits of our capabilities with current instrumentation in transmission spectroscopy and challenge our state-of-the-art statistical techniques. Here we present the transmission spectrum of the temperate super-Earth LHS 1140b usi…
Detection and Bulk Properties of the HR 8799 Planets with High-resolution Spectroscopy
Knutson, Heather; Duchêne, Gaspard; Fitzgerald, Michael P. +49 more
Using the Keck Planet Imager and Characterizer, we obtained high-resolution (R ~ 35,000) K-band spectra of the four planets orbiting HR 8799. We clearly detected H2O and CO in the atmospheres of HR 8799 c, d, and e, and tentatively detected a combination of CO and H2O in b. These are the most challenging directly imaged exopl…
The Solar Neighborhood XLVIII: Nine Giant Planets Orbiting Nearby K Dwarfs, and the CHIRON Spectrograph's Radial Velocity Performance
Gies, Douglas R.; Quinn, Samuel N.; Henry, Todd J. +5 more
We report initial results of a large radial velocity survey of K dwarfs up to a distance of 50 pc from the solar system, to look for stellar, brown dwarf, and Jovian planets using radial velocities from the CHIRON spectrograph on the CTIO/SMARTS 1.5 m telescope. We identify three new exoplanet candidates orbiting host stars in the K dwarf survey a…