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The Open Cluster Chemical Abundances and Mapping Survey. IV. Abundances for 128 Open Clusters Using SDSS/APOGEE DR16
DOI: 10.3847/1538-3881/ab77bc Bibcode: 2020AJ....159..199D

Bizyaev, Dmitry; Brownstein, Joel R.; Pan, Kaike +22 more

The Open Cluster Chemical Abundances and Mapping (OCCAM) survey aims to constrain key Galactic dynamical and chemical evolution parameters by the construction of a large, comprehensive, uniform, infrared-based spectroscopic data set of hundreds of open clusters. This fourth contribution from the OCCAM survey presents analysis using Sloan Digital S…

2020 The Astronomical Journal
Gaia 120
Flare Statistics for Young Stars from a Convolutional Neural Network Analysis of TESS Data
DOI: 10.3847/1538-3881/abac0a Bibcode: 2020AJ....160..219F

Schlieder, Joshua E.; Günther, Maximilian N.; Montet, Benjamin T. +5 more

All-sky photometric time-series missions have allowed for the monitoring of thousands of young (tage < 800 Myr) stars in order to understand the evolution of stellar activity. Here, we developed a convolutional neural network (CNN), stella, specifically trained to find flares in Transiting Exoplanet Survey Satellite (TESS) short-cade…

2020 The Astronomical Journal
Gaia 109
The First Habitable-zone Earth-sized Planet from TESS. I. Validation of the TOI-700 System
DOI: 10.3847/1538-3881/aba4b2 Bibcode: 2020AJ....160..116G

Kostov, Veselin B.; Barclay, Thomas; Vanderburg, Andrew +92 more

We present the discovery and validation of a three-planet system orbiting the nearby (31.1 pc) M2 dwarf star TOI-700 (TIC 150428135). TOI-700 lies in the TESS continuous viewing zone in the Southern Ecliptic Hemisphere; observations spanning 11 sectors reveal three planets with radii ranging from 1 R to 2.6 R and orbital pe…

2020 The Astronomical Journal
Gaia 107
Searching the Entirety of Kepler Data. II. Occurrence Rate Estimates for FGK Stars
DOI: 10.3847/1538-3881/ab88b0 Bibcode: 2020AJ....159..248K

Kunimoto, Michelle; Matthews, Jaymie M.

We present exoplanet occurrence rates estimated with approximate Bayesian computation for planets with radii between 0.5 and 16 R and orbital periods between 0.78 and 400 days orbiting FGK dwarf stars. We base our results on an independent planet catalog compiled from our search of all ∼200,000 stars observed over the Kepler mission, w…

2020 The Astronomical Journal
Gaia 101
Untangling the Galaxy. II. Structure within 3 kpc
DOI: 10.3847/1538-3881/abc0e6 Bibcode: 2020AJ....160..279K

Stassun, Keivan G.; Kounkel, Marina; Covey, Kevin

We present the results of the hierarchical clustering analysis of the Gaia DR2 data to search for clusters, comoving groups, and other stellar structures. The current paper builds on the sample from the previous work, extending it in distance from 1 to 3 kpc and increasing the number of identified structures up to 8292. To aid in the analysis of t…

2020 The Astronomical Journal
Gaia 99
High-precision Dark Halo Virial Masses from Globular Cluster Numbers: Implications for Globular Cluster Formation and Galaxy Assembly
DOI: 10.3847/1538-3881/ab5b0e Bibcode: 2020AJ....159...56B

Forbes, Duncan A.; Burkert, Andreas

We confirm that the number of globular clusters (GCs), NGC, is an excellent tracer of their host galaxy's halo virial mass, Mvir. The simple linear relation Mvir = 5 × 109 M × NGC fits the data perfectly from Mvir = 1010 M to Mvir = 2 × …

2020 The Astronomical Journal
eHST 93
TESS Hunt for Young and Maturing Exoplanets (THYME). II. A 17 Myr Old Transiting Hot Jupiter in the Sco-Cen Association
DOI: 10.3847/1538-3881/ab94b7 Bibcode: 2020AJ....160...33R

Vanderburg, Andrew; Quinn, Samuel N.; Law, Nicholas M. +10 more

We present the discovery of a transiting hot Jupiter orbiting HIP 67522 (Teff ∼ 5650 K; M* ∼ 1.2M) in the 10-20 Myr old Sco-Cen OB association. We identified the transits in the TESS data using our custom notch filter planet search pipeline and characterize the system with additional photometry from Spitzer; spect…

2020 The Astronomical Journal
Gaia 93
Debris Disk Results from the Gemini Planet Imager Exoplanet Survey's Polarimetric Imaging Campaign
DOI: 10.3847/1538-3881/ab9199 Bibcode: 2020AJ....160...24E

Matthews, Brenda C.; Duchêne, Gaspard; Esposito, Thomas M. +62 more

We report the results of a ∼4 yr direct imaging survey of 104 stars to resolve and characterize circumstellar debris disks in scattered light as part of the Gemini Planet Imager (GPI) Exoplanet Survey. We targeted nearby (≲150 pc), young (≲500 Myr) stars with high infrared (IR) excesses (LIR/L > 10-5), includin…

2020 The Astronomical Journal
Gaia Herschel eHST 92
The Featureless Transmission Spectra of Two Super-puff Planets
DOI: 10.3847/1538-3881/ab5d36 Bibcode: 2020AJ....159...57L

Fortney, Jonathan J.; Désert, Jean-Michel; Line, Michael R. +9 more

The Kepler mission revealed a class of planets known as "super-puffs," with masses only a few times larger than Earth's but radii larger than Neptune, giving them very low mean densities. All three of the known planets orbiting the young solar-type star Kepler 51 are super-puffs. The Kepler 51 system thereby provides an opportunity for a comparati…

2020 The Astronomical Journal
Gaia eHST 90
TESS Hunt for Young and Maturing Exoplanets (THYME). III. A Two-planet System in the 400 Myr Ursa Major Group
DOI: 10.3847/1538-3881/abae64 Bibcode: 2020AJ....160..179M

Gagliano, Robert; Kristiansen, Martti H.; LaCourse, Daryll M. +51 more

Exoplanets can evolve significantly between birth and maturity, as their atmospheres, orbits, and structures are shaped by their environment. Young planets (<1 Gyr) offer an opportunity to probe the critical early stages of this evolution, where planets evolve the fastest. However, most of the known young planets orbit prohibitively faint stars…

2020 The Astronomical Journal
Gaia 89