Search Publications

Variability in the Massive Open Cluster NGC 1817 from K2: A Rich Population of Asteroseismic Red Clump, Eclipsing Binary, and Main-sequence Pulsating Stars
DOI: 10.3847/1538-3881/ab68df Bibcode: 2020AJ....159...96S

Vanderburg, Andrew; Stello, Dennis; Grundahl, Frank +13 more

We present a survey of variable stars detected in K2 Campaign 13 within the massive intermediate-age (∼1 Gyr) open cluster NGC 1817. We identify a complete sample of 44 red clump stars in the cluster, and have measured asteroseismic quantities (νmax and/or Δν) for 29 of them. Five stars showed suppressed dipole modes, and the occurrence…

2020 The Astronomical Journal
Gaia 13
TIC 278956474: Two Close Binaries in One Young Quadruple System Identified by TESS
DOI: 10.3847/1538-3881/ab9d20 Bibcode: 2020AJ....160...76R

Borkovits, Tamás; Hellier, Coel; Latham, David W. +25 more

We have identified a quadruple system with two close eclipsing binaries in Transiting Exoplanet Survey Satellite (TESS) data. The object is unresolved in Gaia and appears as a single source at parallax 1.08 ± 0.01 mas. Both binaries have observable primary and secondary eclipses and were monitored throughout TESS Cycle 1 (sectors 1-13), falling wi…

2020 The Astronomical Journal
Gaia 13
Fine Structures in the Main Sequence Revealed by Gaia Data Release 2
DOI: 10.3847/1538-3881/aba192 Bibcode: 2020AJ....160..102J

Jao, Wei-Chun; Feiden, Gregory A.

The Hertzsprung-Russell diagram (HRD) is fully examined using the Fourier analysis. This work shows more stars are above the gap in the lower main sequence than below it, and this implies that stars spend more time above the gap while they undergo variability associated with the 3He instability. The enhanced HRD also shows the width of …

2020 The Astronomical Journal
Gaia 13
HATS-47b, HATS-48Ab, HATS-49b, and HATS-72b: Four Warm Giant Planets Transiting K Dwarfs
DOI: 10.3847/1538-3881/ab7821 Bibcode: 2020AJ....159..173H

Latham, David W.; Jordán, Andrés; Butler, R. P. +43 more

We report the discovery of four transiting giant planets around K dwarfs. The planets HATS-47b, HATS-48Ab, HATS-49b, and HATS-72b have masses of ${0.369}_{-0.021}^{+0.031} ${M}_{{\rm{J}}}, ${0.243}_{-0.030}^{+0.022} ${M}_{{\rm{J}}}, ${0.353}_{-0.027}^{+0.038} ${M}_{{\rm{J}}}, and $0.1254\pm 0.0039 ${M}_{{\rm{J}}}, respectively, and radii of $1.117…

2020 The Astronomical Journal
Gaia 12
The Sizes of z ∼ 9-10 Galaxies Identified in the Brightest of Reionizing Galaxies (BoRG) Survey
DOI: 10.3847/1538-3881/aba617 Bibcode: 2020AJ....160..154H

Holwerda, Benne W.; Bradley, Larry; Livermore, Rachael +5 more

Redshift z = 9-10 object selection is the effective limit of Hubble Space Telescope (HST) imaging capability, even when confirmed with Spitzer. If only a few photometry data points are available, it becomes attractive to add criteria based on their morphology in these J- and H-band images. One could do so through visual inspection, a size criterio…

2020 The Astronomical Journal
eHST 12
First Resolved Scattered-light Images of Four Debris Disks in Scorpius-Centaurus with the Gemini Planet Imager
DOI: 10.3847/1538-3881/ab5af2 Bibcode: 2020AJ....159...31H

Matthews, Brenda C.; Duchêne, Gaspard; Esposito, Thomas M. +57 more

We present the first spatially resolved scattered-light images of four debris disks around members of the Scorpius-Centaurus (Sco-Cen) OB association with high-contrast imaging and polarimetry using the Gemini Planet Imager (GPI). All four disks are resolved for the first time in polarized light, and one disk is also detected in total intensity. T…

2020 The Astronomical Journal
Gaia 12
HATS-37Ab and HATS-38b: Two Transiting Hot Neptunes in the Desert
DOI: 10.3847/1538-3881/aba530 Bibcode: 2020AJ....160..222J

Butler, R. P.; Henning, Th.; Mancini, L. +24 more

We report the discovery of two transiting Neptunes by the HATSouth survey. The planet HATS-37Ab has a mass of $0.099\pm 0.042$ ${M}_{{\rm{J}}}$ (31.5 ± 13.4 M) and a radius of $0.606\pm 0.016$ ${R}_{{\rm{J}}}$ , and is on a $P=4.3315$ day orbit around a $V=12.266\pm 0.030$ mag, ${0.843}_{-0.012}^{+0.017}$ ${M}_{\odot }$ star with a rad…

2020 The Astronomical Journal
Gaia 12
High-contrast Thermal Infrared Spectroscopy with ALES: The 3-4 µm Spectrum of κ Andromedae b
DOI: 10.3847/1538-3881/abbef3 Bibcode: 2020AJ....160..262S

Spalding, Eckhart; Barman, Travis; Woodward, Charles E. +7 more

We present the first L-band (2.8-4.1 µm) spectroscopy of κ Andromedae b, a ∼20 MJup companion orbiting at 1″ projected separation from its B9-type stellar host. We combine our Large Binocular Telescope (LBT) Arizona Lenslets for Exoplanet Spectroscopy (ALES) integral field spectrograph data with measurements from other instruments…

2020 The Astronomical Journal
Gaia 12
Sensitivity Analyses of Exoplanet Occurrence Rates from Kepler and Gaia
DOI: 10.3847/1538-3881/ab90fe Bibcode: 2020AJ....160...16S

Bryson, Steve; Huber, Daniel; Batalha, Natalie +11 more

We infer the number of planets per star as a function of orbital period and planet size using Kepler archival data products with updated stellar properties from the Gaia Data Release 2. Using hierarchical Bayesian modeling and Hamiltonian Monte Carlo, we incorporate planet radius uncertainties into an inhomogeneous Poisson point process model. We …

2020 The Astronomical Journal
Gaia 12
OGLE-2018-BLG-1269Lb: A Jovian Planet with a Bright I = 16 Host
DOI: 10.3847/1538-3881/abacc8 Bibcode: 2020AJ....160..148J

Han, Cheongho; Udalski, Andrzej; Lee, Chung-Uk +57 more

We report the discovery of a planet in the microlensing event OGLE-2018-BLG-1269 with a planet-host mass ratio q ∼ 6 × 10-4, i.e., 0.6 times smaller than the Jupiter/Sun mass ratio. Combined with the Gaia parallax and proper motion, a strong one-dimensional constraint on the microlens parallax vector allows us to significantly reduce th…

2020 The Astronomical Journal
Gaia 12