Search Publications
The Outburst of the Young Star Gaia19bey
Lin, Chien-Cheng; Tonry, John; Magnier, Eugene +10 more
We report photometry and spectroscopy of the outburst of the young stellar object Gaia19bey. We have established the outburst light curve with archival Gaia "G," ATLAS "Orange," Zwicky Transient Facility r-band, and Pan-STARRS "rizy"-filter photometry, showing an outburst of ~4 yr duration, longer than typical EX Lupi objects but shorter than FU O…
A Fast, Two-dimensional Gaussian Process Method Based on Celerite: Applications to Transiting Exoplanet Discovery and Characterization
Foreman-Mackey, Daniel; Gordon, Tyler A.; Agol, Eric
Gaussian processes (GPs) are commonly used as a model of stochastic variability in astrophysical time series. In particular, GPs are frequently employed to account for correlated stellar variability in planetary transit light curves. The efficient application of GPs to light curves containing thousands to tens of thousands of data points has been …
A Rotation Rate for the Planetary-mass Companion DH Tau b
Knutson, Heather A.; Morley, Caroline V.; Bowler, Brendan P. +3 more
DH Tau b is a young planetary-mass companion orbiting at a projected separation of 320 au from its ∼2 Myr old host star DH Tau. With an estimated mass of 8-22 ${M}_{\mathrm{Jup}}$ this object straddles the deuterium-burning limit, and might have formed via core or pebble accretion, disk instability, or molecular cloud fragmentation. To shed light …
Bayesian Approach for Determining Microlens System Properties with High-angular-resolution Follow-up Imaging
Bennett, David P.; Koshimoto, Naoki; Suzuki, Daisuke
We present the details of the Bayesian analysis of the planetary microlensing event MOA-2016-BLG-227, whose excess flux is likely due to a source/lens companion or an unrelated ambient star, as well as of the assumed prior distributions. Furthermore, we apply this method to four reported planetary events, MOA-2008-BLG-310, MOA-2011-BLG-293, OGLE-2…
OGLE-2017-BLG-0406: Spitzer Microlens Parallax Reveals Saturn-mass Planet Orbiting M-dwarf Host in the Inner Galactic Disk
Soszyński, I.; Szymański, M. K.; Pietrukowicz, P. +100 more
We report the discovery and analysis of the planetary microlensing event OGLE-2017-BLG-0406, which was observed both from the ground and by the Spitzer satellite in a solar orbit. At high magnification, the anomaly in the light curve was densely observed by ground-based-survey and follow-up groups, and it was found to be explained by a planetary l…
A Mini-Neptune and a Radius Valley Planet Orbiting the Nearby M2 Dwarf TOI-1266 in Its Venus Zone: Validation with the Habitable-zone Planet Finder
Cochran, William D.; Endl, Michael; Mahadevan, Suvrath +26 more
We report on the validation of two planets orbiting the nearby (36 pc) M2 dwarf TOI-1266 observed by the TESS mission. This system is one of a few M dwarf multiplanet systems with close-in planets where the inner planet is substantially larger than the outer planet. The inner planet is sub-Neptune-sized (R = 2.46 ± 0.08 R⊕) with an orbi…
ACCESS: Confirmation of No Potassium in the Atmosphere of WASP-31b
Fortney, Jonathan J.; Kirk, James; López-Morales, Mercedes +12 more
We present a new optical (400-950 nm) transmission spectrum of the hot Jupiter WASP-31b (M = 0.48 MJ; R = 1.54 RJ; P = 3.41 days), obtained by combining four transit observations. These transits were observed with IMACS on the Magellan Baade Telescope at Las Campanas Observatory as part of the ACCESS project. We investigate t…
Spectroscopic Orbits of 11 Nearby, Mid-to-late M-dwarf Binaries
Latham, David W.; Berlind, Perry; Calkins, Michael L. +7 more
We present the spectroscopic orbits of 11 nearby, mid-to-late M dwarf binary systems in a variety of configurations: 2 single-lined binaries (SB1s), 7 double-lined binaries (SB2s), 1 double-lined triple (ST2), and 1 triple-lined triple (ST3). Eight of these orbits are the first published for these systems, while five are newly identified multiples…
A Census of Star Formation in the Outer Galaxy. II. The GLIMPSE360 Field
Hora, Joseph L.; Tolls, Volker; Winston, Elaine
We have conducted a study of star formation in the outer Galaxy from 65°< l < 265° in the region observed by the GLIMPSE360 program. This Spitzer warm mission program mapped the plane of the outer Milky Way with IRAC at 3.6 and 4.5 µm. We combine the IRAC, Wide-field Infrared Survey Explorer (WISE), and Two Micron All Sky Survey catalo…
Endogenic and Exogenic Contributions to Visible-wavelength Spectra of Europa's Trailing Hemisphere
Brown, Michael E.; Hand, Kevin P.; Trumbo, Samantha K.
The composition of Europa's trailing hemisphere reflects the combined influences of endogenous geologic resurfacing and exogenous sulfur radiolysis. Using spatially resolved visible-wavelength spectra of Europa obtained with the Hubble Space Telescope, we map multiple spectral features across the trailing hemisphere and compare their geographies w…