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The Orbital Architecture and Debris Disks of the HR 8799 Planetary System
Goździewski, Krzysztof; Migaszewski, Cezary
The HR 8799 planetary system with four ≃10 m Jup planets in wide orbits up to ≃70 au and orbital periods up to 500 yr has been detected with direct imaging. Its intriguing orbital architecture is not yet fully resolved due to time-limited astrometry covering only ≃20 yr. Earlier, we constructed a heuristic model of the system based on r…
The Second Data Release of the Beijing-Arizona Sky Survey
Myers, Adam D.; Fan, Xiaohui; Jiang, Linhua +29 more
This paper describes the second data release (DR2) of the Beijing-Arizona Sky Survey (BASS). BASS is an imaging survey covering a 5400 deg2 footprint in the g and r bands using the 2.3 m Bok telescope. DR2 includes the observations through 2017 July obtained by BASS and by the Mayall z-band Legacy Survey (MzLS), which used the 4 m Mayal…
A TESS Dress Rehearsal: Planetary Candidates and Variables from K2 Campaign 17
Bieryla, Allyson; Latham, David W.; Quinn, Samuel N. +40 more
We produce light curves for all ∼34,000 targets observed with K2 in Campaign 17 (C17), identifying 34 planet candidates, 184 eclipsing binaries, and 222 other periodic variables. The forward-facing direction of the C17 field means follow-up can begin immediately now that the campaign has concluded and interesting targets have been identified. The …
Spitzer Observations of the North Ecliptic Pole
Im, M.; Lee, H. M.; Clements, D. L. +19 more
We present a photometric catalog for Spitzer Space Telescope warm mission observations of the North Ecliptic Pole (NEP; centered at R.A. = 18h00m00s, decl. = 66d33m38.ˢ552). The observations are conducted with IRAC in the 3.6 and 4.5 µm bands over an area of 7.04 deg2, reachin…
Abundances and Depletions of Neutron-capture Elements in the Interstellar Medium
Lambert, D. L.; Federman, S. R.; Ritchey, A. M.
We present an extensive analysis of the gas-phase abundances and depletion behaviors of neutron-capture elements in the interstellar medium (ISM). Column densities (or upper limits to the column densities) of Ga II, Ge II, As II, Kr I, Cd II, Sn II, and Pb II are determined for a sample of 69 sight lines with high- and/or medium-resolution archiva…
The UV Emission of Stars in the LAMOST Survey. I. Catalogs
Zhang, Yong; Bai, Yu; Wang, Song +11 more
We present the ultraviolet magnitudes for over three million stars in the LAMOST survey, in which 2,202,116 stars are detected by GALEX. For 889,235 undetected stars, we develop a method to estimate their upper limit magnitudes. The distribution of (FUV - NUV) shows that the color declines with increasing effective temperature for stars hotter tha…
Comparing Chandra and Hubble in the Northern Disk of M31
Williams, Benjamin F.; Eracleous, Michael; Sasaki, Manami +9 more
The X-ray source populations within galaxies are typically difficult to identify and classify with X-ray data alone. We are able to break through this barrier by combining deep new Chandra ACIS-I observations with extensive Hubble Space Telescope (HST) imaging from the Panchromatic Hubble Andromeda Treasury of the M31 disk. We detect 373 X-ray sou…
Multiple Stellar Populations of Globular Clusters from Homogeneous Ca-CN Photometry. III. NGC 6752
Lee, Jae-Woo
We present a multiple stellar population study of the globular cluster NGC 6752. We show that our new photometric CN index accurately traces the CN and the nitrogen abundances in cool giants, finding the discrete double red giant branch (RGB) and asymptotic giant branch (AGB) sequences with number ratios between the CN-weak and the CN-strong popul…
Revised Exoplanet Radii and Habitability Using Gaia Data Release 2
Wittenmyer, Robert A.; Horner, Jonathan; Wright, Duncan J. +4 more
Accurate stellar properties are crucial for determining exoplanet characteristics. Gaia DR2 presents revised distances, luminosities, and radii for 1.6 billion stars. Here, we report the calculation of revised radii and densities for 320 non-Kepler exoplanets using this data and present updated calculations of the incident flux received by 690 kno…
Transition Probabilities of Co II Weak Lines to the Ground and Low Metastable Levels
Sneden, C.; Lawler, J. E.; Cowan, J. J. +2 more
New branching fraction (BF) measurements based primarily on data from a cross-dispersed echelle spectrometer are reported for 84 lines of Co II. The BFs for 82 lines are converted to absolute atomic transition probabilities using radiative lifetimes from laser-induced fluorescence (LIF) measurements on 19 upper levels of the lines. A lifetime of 3…