Search Publications

APOGEE Net: Improving the Derived Spectral Parameters for Young Stars through Deep Learning
DOI: 10.3847/1538-3881/ab7a97 Bibcode: 2020AJ....159..182O

Stassun, Keivan G.; Kounkel, Marina; Covey, K. R. +6 more

Machine learning allows for efficient extraction of physical properties from stellar spectra that have been obtained by large surveys. The viability of machine-learning approaches has been demonstrated for spectra covering a variety of wavelengths and spectral resolutions, but most often for main-sequence (MS) or evolved stars, where reliable synt…

2020 The Astronomical Journal
Gaia 45
Plateau de Bure High-z Blue Sequence Survey 2 (PHIBSS2): Search for Secondary Sources, CO Luminosity Functions in the Field, and the Evolution of Molecular Gas Density through Cosmic Time
DOI: 10.3847/1538-3881/ab7458 Bibcode: 2020AJ....159..190L

Lenkić, Laura; Bolatto, Alberto D.; Neri, Roberto +8 more

We report on the results of a search for serendipitous sources in CO emission in 110 cubes targeting CO(2 - 1), CO(3 - 2), and CO(6 - 5) at z ∼ 1-2 from the second Plateau de Bure High-z Blue Sequence Survey (PHIBSS2). The PHIBSS2 observations were part of a 4 yr legacy program at the IRAM Plateau de Bure Interferometer aimed at studying early gal…

2020 The Astronomical Journal
eHST 45
Near-ultraviolet Transmission Spectroscopy of HD 209458b: Evidence of Ionized Iron Beyond the Planetary Roche Lobe
DOI: 10.3847/1538-3881/ab6a0b Bibcode: 2020AJ....159..111C

France, Kevin; Cubillos, Patricio E.; Koskinen, Tommi +5 more

The inflated transiting hot Jupiter HD 209458b is one of the best studied objects since the beginning of exoplanet characterization. Transmission observations of this system between the mid-infrared and the far-ultraviolet have revealed the signature of atomic, molecular, and possibly aerosol species in the lower atmosphere of the planet, as well …

2020 The Astronomical Journal
Gaia eHST 44
ARES. III. Unveiling the Two Faces of KELT-7 b with HST WFC3
DOI: 10.3847/1538-3881/aba000 Bibcode: 2020AJ....160..112P

Drossart, Pierre; Beaulieu, Jean-Philippe; Changeat, Quentin +24 more

We present the analysis of the hot-Jupiter KELT-7 b using transmission and emission spectroscopy from the Hubble Space Telescope, both taken with the Wide Field Camera 3. Our study uncovers a rich transmission spectrum that is consistent with a cloud-free atmosphere and suggests the presence of H2O and H-. In contrast, the ex…

2020 The Astronomical Journal
eHST 44
TOI-677b: A Warm Jupiter (P = 11.2 days) on an Eccentric Orbit Transiting a Late F-type Star
DOI: 10.3847/1538-3881/ab6f67 Bibcode: 2020AJ....159..145J

Trifonov, Trifon; Henning, Thomas; Barclay, Thomas +46 more

We report the discovery of TOI-677 b, first identified as a candidate in light curves obtained within Sectors 9 and 10 of the Transiting Exoplanet Survey Satellite (TESS) mission and confirmed with radial velocities. TOI-677 b has a mass of ${\text{}}{M}_{{\text{}}p} = ${1.236}_{-0.067}^{+0.069} ${\text{}}{M}_{{\rm{J}}}, a radius of ${\text{}}{R}_…

2020 The Astronomical Journal
Gaia 44
Analysis of Membership Probability in Nearby Young Moving Groups with Gaia DR2
DOI: 10.3847/1538-3881/ab76d6 Bibcode: 2020AJ....159..166U

Mathew, Blesson; Manoj, P.; Ujjwal, K. +2 more

We analyze the membership probability of young stars belonging to nearby moving groups with Gaia DR2 data. The sample of 1429 stars was identified from "The Catalog of Suspected Nearby Young Moving Group Stars." Good-quality parallax and proper motion values were retrieved for 890 stars from the Gaia DR2 database. The analysis for membership proba…

2020 The Astronomical Journal
Gaia 43
An Updated Small Magellanic Cloud and Magellanic Bridge Catalog of Star Clusters, Associations, and Related Objects
DOI: 10.3847/1538-3881/ab6595 Bibcode: 2020AJ....159...82B

Barbuy, Beatriz; Bica, Eduardo; Santos, João F. C., Jr. +5 more

We present a catalog of star clusters, associations, and related extended objects in the Small Magellanic Cloud (SMC) and the Magellanic Bridge with 2741 entries, a factor 2 more than a previous version from a decade ago. Literature data up until 2018 December are included. The identification of star clusters was carried out with digital atlases i…

2020 The Astronomical Journal
Gaia 43
TOI-503: The First Known Brown-dwarf Am-star Binary from the TESS Mission
DOI: 10.3847/1538-3881/ab7245 Bibcode: 2020AJ....159..151S

Barclay, Thomas; Latham, David W.; Quinn, Samuel N. +78 more

We report the discovery of an intermediate-mass transiting brown dwarf (BD), TOI-503b, from the TESS mission. TOI-503b is the first BD discovered by TESS, and it has circular orbit around a metallic-line A-type star with a period of P = 3.6772 ± 0.0001 days. The light curve from TESS indicates that TOI-503b transits its host star in a grazing mann…

2020 The Astronomical Journal
Gaia 43
A Free-floating or Wide-orbit Planet in the Microlensing Event OGLE-2019-BLG-0551
DOI: 10.3847/1538-3881/ab8aeb Bibcode: 2020AJ....159..262M

Han, Cheongho; Udalski, Andrzej; Lee, Chung-Uk +32 more

High-cadence observations of the Galactic bulge by the microlensing surveys led to the discovery of a handful of extremely short-timescale microlensing events that can be attributed to free-floating or wide-orbit planets. Here, we report the discovery of another strong free-floating planet candidate, which was found from the analysis of the gravit…

2020 The Astronomical Journal
Gaia eHST 43
Size and Shape Constraints of (486958) Arrokoth from Stellar Occultations
DOI: 10.3847/1538-3881/ab6ced Bibcode: 2020AJ....159..130B

Dunham, David W.; Tanga, Paolo; Singer, Kelsi N. +130 more

We present the results from four stellar occultations by (486958) Arrokoth, the flyby target of the New Horizons extended mission. Three of the four efforts led to positive detections of the body, and all constrained the presence of rings and other debris, finding none. Twenty-five mobile stations were deployed for 2017 June 3 and augmented by fix…

2020 The Astronomical Journal
Gaia eHST 42