Search Publications
Revised and New Proper Motions for Confirmed and Candidate Milky Way Dwarf Galaxies
McConnachie, Alan W.; Venn, Kim A.
A new derivation of systemic proper motions of Milky Way satellites is presented and applied to 59 confirmed or candidate dwarf galaxy satellites using Gaia Data Release 2. This constitutes all known Milky Way dwarf galaxies (and likely candidates) as of 2020 May, except for the Magellanic Clouds, the Canis Major and Hydra 1 stellar overdensities,…
New Grids of Pure-hydrogen White Dwarf NLTE Model Atmospheres and the HST/STIS Flux Calibration
Rauch, Thomas; Hubeny, Ivan; Bohlin, Ralph C.
Nonlocal thermodynamic equilibrium (NLTE) calculations of hot white dwarf (WD) model atmospheres are the cornerstone of modern flux calibrations for the Hubble Space Telescope and for the CALSPEC database. These theoretical spectral energy distributions (SEDs) provide the relative flux versus wavelength, and only the absolute flux level remains to…
Rotation of Low-mass Stars in Taurus with K2
Bouvier, J.; Rebull, L. M.; Stauffer, J. R. +4 more
We present an analysis of K2 light curves (LCs) from Campaigns 4 and 13 for members of the young (∼3 Myr) Taurus association, in addition to an older (∼30 Myr) population of stars that is largely in the foreground of the Taurus molecular clouds. Out of 156 of the highest-confidence Taurus members, we find that 81% are periodic. Our sample of young…
A Pair of TESS Planets Spanning the Radius Valley around the Nearby Mid-M Dwarf LTT 3780
López-Morales, Mercedes; Latham, David W.; Quinn, Samuel N. +84 more
We present the confirmation of two new planets transiting the nearby mid-M dwarf LTT 3780 (TIC 36724087, TOI-732, V = 13.07, Ks = 8.204, Rs = 0.374 R⊙, Ms = 0.401 M⊙, d = 22 pc). The two planet candidates are identified in a single Transiting Exoplanet Survey Satellite sector and validated wit…
Keck/NIRC2 L'-band Imaging of Jovian-mass Accreting Protoplanets around PDS 70
Baranec, Christoph; Jensen-Clem, Rebecca; Duchêne, Gaspard +42 more
We present L'-band imaging of the PDS 70 planetary system with Keck/NIRC2 using the new infrared pyramid wave front sensor. We detected both PDS 70 b and c in our images, as well as the front rim of the circumstellar disk. After subtracting off a model of the disk, we measured the astrometry and photometry of both planets. Placing priors based on …
TOI-1338: TESS' First Transiting Circumbinary Planet
Trifonov, Trifon; Kostov, Veselin B.; Torres, Guillermo +65 more
We report the detection of the first circumbinary planet (CBP) found by Transiting Exoplanet Survey Satellite (TESS). The target, a known eclipsing binary, was observed in sectors 1 through 12 at 30 minute cadence and in sectors 4 through 12 at 2 minute cadence. It consists of two stars with masses of 1.1 M⊙ and 0.3 M⊙ on a s…
Refining the Census of the Upper Scorpius Association with Gaia
Luhman, K. L.; Esplin, T. L.
We have refined the census of stars and brown dwarfs in the Upper Sco association (∼10 Myr, ∼145 pc) by (1) updating the selection of candidate members from our previous survey to include the high-precision astrometry from the second data release of Gaia, (2) obtaining spectra of a few hundred candidate members to measure their spectral types and …
A Probabilistic Approach to Kepler Completeness and Reliability for Exoplanet Occurrence Rates
Huber, D.; Mullally, S. E.; Berger, T. +5 more
Exoplanet catalogs produced by surveys suffer from a lack of completeness (not every planet is detected) and less than perfect reliability (not every planet in the catalog is a true planet), particularly near the survey's detection limit. Exoplanet occurrence rate studies based on such a catalog must be corrected for completeness and reliability. …
The Southern Stellar Stream Spectroscopic Survey (S5): Chemical Abundances of Seven Stellar Streams
Lewis, Geraint F.; Casey, Andrew R.; Hattori, Kohei +16 more
We present high-resolution Magellan/MIKE spectroscopy of 42 red giant stars in seven stellar streams confirmed by the Southern Stellar Stream Spectroscopic Survey (S5): ATLAS, Aliqa Uma, Chenab, Elqui, Indus, Jhelum, and Phoenix. Abundances of 30 elements have been derived from over 10,000 individual line measurements or upper limits us…
Architectures of Exoplanetary Systems. III. Eccentricity and Mutual Inclination Distributions of AMD-stable Planetary Systems
Ford, Eric B.; Ragozzine, Darin; He, Matthias Y. +1 more
The angular momentum deficit (AMD) of a planetary system is a measure of its orbital excitation and a predictor of long-term stability. We adopt the AMD-stability criterion to constrain the orbital architectures for exoplanetary systems. Previously, He et al. showed through forward modeling (SysSim) that the observed multiplicity distribution can …