Search Publications

On the Ubiquity and Stellar Luminosity Dependence of Exocometary CO Gas: Detection around M Dwarf TWA 7
DOI: 10.3847/1538-3881/aaff5b Bibcode: 2019AJ....157..117M

Bayo, A.; Wilner, D. J.; Olofsson, J. +2 more

Millimeter observations of CO gas in planetesimal belts show a high detection rate around A stars, but few detections for later type stars. We present the first CO detection in a planetesimal belt around an M star, TWA 7. The optically thin CO (J = 3-2) emission is colocated with previously identified dust emission from the belt, and the emission …

2019 The Astronomical Journal
Gaia eHST 43
HATS-60b-HATS-69b: 10 Transiting Planets from HATSouth
DOI: 10.3847/1538-3881/aaf8b6 Bibcode: 2019AJ....157...55H

Arriagada, P.; Butler, R. P.; Henning, Th. +27 more

We report the discovery of 10 transiting extrasolar planets by the HATSouth survey. The planets range in mass from the super-Neptune HATS-62b, with {M}p< 0.179 {M}{{J}}, to the super-Jupiter HATS-66b, with {M}p=5.33 {M}{{J}}, and in size from the Saturn HATS-69b, with {R}p=0.94 {R}{{J<…

2019 The Astronomical Journal
Gaia 41
Distant Comet C/2017 K2 and the Cohesion Bottleneck
DOI: 10.3847/1538-3881/aaf38c Bibcode: 2019AJ....157...65J

Mutchler, Max; Jewitt, David; Agarwal, Jessica +3 more

The distant long-period comet C/2017 K2 (PANSTARRS) has been outside the planetary region of the solar system for ∼3 Myr, negating the possibility that heat retained from the previous perihelion could be responsible for its activity. This inbound comet is also too cold for water ice to sublimate and too cold for amorphous water ice, if present, to…

2019 The Astronomical Journal
eHST 40
Long-period Giant Companions to Three Compact, Multiplanet Systems
DOI: 10.3847/1538-3881/ab0899 Bibcode: 2019AJ....157..145M

Fulton, Benjamin J.; Hirsch, Lea A.; Howard, Andrew W. +7 more

Understanding the relationship between long-period giant planets and multiple smaller short-period planets is critical for formulating a complete picture of planet formation. This work characterizes three such systems. We present Kepler-65, a system with an eccentric (e = 0.28 ± 0.07) giant planet companion discovered via radial velocities (RVs) e…

2019 The Astronomical Journal
Gaia 39
Revisiting the Long-period Transiting Planets from Kepler
DOI: 10.3847/1538-3881/ab1f70 Bibcode: 2019AJ....157..248H

Zhu, Wei; Wu, Yanqin; Herman, Miranda K.

Currently, we have only limited means to probe the presence of planets at large orbital separations. Foreman-Mackey et al. searched for long-period transiting planets in the Kepler light curves using an automated pipeline. Here, we apply their pipeline, with minor modifications, to a larger sample and use updated stellar parameters from Gaia DR2. …

2019 The Astronomical Journal
Gaia 39
First ALMA Millimeter-wavelength Maps of Jupiter, with a Multiwavelength Study of Convection
DOI: 10.3847/1538-3881/ab3643 Bibcode: 2019AJ....158..139D

de Pater, Imke; Sault, R. J.; Wong, Michael H. +15 more

We obtained the first maps of Jupiter at 1-3 mm wavelength with the Atacama Large Millimeter/Submillimeter Array (ALMA) on 2017 January 3-5, just days after an energetic eruption at 16.°5S jovigraphic latitude had been reported by the amateur community, and about two to three months after the detection of similarly energetic eruptions in the north…

2019 The Astronomical Journal
eHST 38
A Tail Structure Associated with a Protoplanetary Disk around SU Aurigae
DOI: 10.3847/1538-3881/ab0ae4 Bibcode: 2019AJ....157..165A

Dong, Ruobing; Liu, Sheng-Yuan; Tamura, Motohide +4 more

We present Atacama Large Millimeter/submillimeter Array observations of the CO (J = 2 - 1) line emission from a protoplanetary disk around T-Tauri star SU Aurigae (hereafter SU Aur). Previous observations in optical and near-infrared wavelengths find a unique structure in SU Aur. One of the highlights of the observational results is that an extend…

2019 The Astronomical Journal
Gaia 38
Machine Learning Applied to Star-Galaxy-QSO Classification and Stellar Effective Temperature Regression
DOI: 10.3847/1538-3881/aaf009 Bibcode: 2019AJ....157....9B

Bai, Yu; Wang, Song; Yang, Fan +1 more

In modern astrophysics, machine learning has increasingly gained popularity with its incredibly powerful ability to make predictions or calculated suggestions for large amounts of data. We describe an application of the supervised machine-learning algorithm, random forests (RF), to the star/galaxy/QSO classification and the stellar effective tempe…

2019 The Astronomical Journal
Gaia 38
Li Evolution and the Open Cluster NGC 6819: A Correlation between Li Depletion and Spindown in Dwarfs More Massive Than the F-Dwarf Li-Dip
DOI: 10.3847/1538-3881/ab3fad Bibcode: 2019AJ....158..163D

Twarog, Bruce A.; Anthony-Twarog, Barbara J.; Deliyannis, Constantine P. +1 more

Spectroscopy of 333 NGC 6819 stars and Gaia astrometry are used to map Li evolution from the giant branch tip to 0.5 mag below the Li dip. Isochrone comparison with [Fe/H] = -0.04, based upon neural network spectroscopic analysis, produces an age of 2.25 (2.4) Gyr for E(B - V) = 0.16 (0.14) and (m - M) = 12.40 (12.29). Despite originating outside …

2019 The Astronomical Journal
Gaia 38
The Physics of the Accelerating Universe Camera
DOI: 10.3847/1538-3881/ab0412 Bibcode: 2019AJ....157..246P

Carretero, Jorge; Castander, Francisco J.; Eriksen, Martin +30 more

The Physics of the Accelerating Universe (PAU) Survey goal is to obtain photometric redshifts (photo-z) and spectral energy distributions (SEDs) of astronomical objects with a resolution roughly one order of magnitude better than current broadband (BB) photometric surveys. To accomplish this, a new large field-of-view (FoV) camera (PAUCam) has bee…

2019 The Astronomical Journal
Gaia 37