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Sixty Validated Planets from K2 Campaigns 5-8
DOI: 10.3847/1538-3881/aae778 Bibcode: 2018AJ....156..277L

Henning, Thomas; Tamura, Motohide; Schlieder, Joshua E. +13 more

We present a uniform analysis of 155 candidates from the second year of NASA’s K2 mission (Campaigns 5-8), yielding 60 statistically validated planets spanning a range of properties with median values of R p = 2.5 {R}\oplus , P = 7.1 days, T eq = 811 K, and J = 11.3 mag. The sample includes 24 planets in 11 mult…

2018 The Astronomical Journal
Gaia 66
The Magellan Evolution of Galaxies Spectroscopic and Ultraviolet Reference Atlas (MegaSaura). I. The Sample and the Spectra
DOI: 10.3847/1538-3881/aaa2ff Bibcode: 2018AJ....155..104R

Dahle, H.; Rigby, J. R.; Bayliss, M. B. +7 more

We introduce Project MEGaSaURA: the Magellan Evolution of Galaxies Spectroscopic and Ultraviolet Reference Atlas. MEGaSaURA comprises medium-resolution, rest-frame ultraviolet spectroscopy of N = 15 bright gravitationally lensed galaxies at redshifts of 1.68 < z < 3.6, obtained with the MagE spectrograph on the Magellan telescopes. The spect…

2018 The Astronomical Journal
eHST 62
Photochemical Haze Formation in the Atmospheres of Super-Earths and Mini-Neptunes
DOI: 10.3847/1538-3881/aac883 Bibcode: 2018AJ....156...38H

Valenti, Jeff A.; Moses, Julianne I.; Marley, Mark S. +8 more

UV radiation can induce photochemical processes in exoplanet atmospheres and produce haze particles. Recent observations suggest that haze and/or cloud layers could be present in the upper atmospheres of exoplanets. Haze particles play an important role in planetary atmospheres and may provide a source of organic material to the surface that may i…

2018 The Astronomical Journal
eHST 61
The Open Cluster Chemical Abundances and Mapping Survey. II. Precision Cluster Abundances for APOGEE Using SDSS DR14
DOI: 10.3847/1538-3881/aad635 Bibcode: 2018AJ....156..142D

Bizyaev, Dmitry; Pan, Kaike; Cunha, Katia +12 more

The Open Cluster Chemical Abundances and Mapping (OCCAM) survey aims to produce a comprehensive, uniform, infrared-based spectroscopic data set for hundreds of open clusters, and to constrain key Galactic dynamical and chemical parameters from this sample. This second contribution from the OCCAM survey presents analysis of 259 member stars with [F…

2018 The Astronomical Journal
Gaia 61
Properties and Occurrence Rates for Kepler Exoplanet Candidates as a Function of Host Star Metallicity from the DR25 Catalog
DOI: 10.3847/1538-3881/aae391 Bibcode: 2018AJ....156..221N

Henning, Thomas; Mathew, Blesson; Manoj, P. +5 more

Correlations between the occurrence rate of exoplanets and their host star properties provide important clues about the planet formation process. We studied the dependence of the observed properties of exoplanets (radius, mass, and orbital period) as a function of their host star metallicity. We analyzed the planetary radii and orbital periods of …

2018 The Astronomical Journal
Gaia 59
Simultaneous Multiwavelength Variability Characterization of the Free-floating Planetary-mass Object PSO J318.5-22
DOI: 10.3847/1538-3881/aaa5a6 Bibcode: 2018AJ....155...95B

Henning, Thomas; Bézard, Bruno; Manjavacas, Elena +15 more

We present simultaneous Hubble Space Telescope (HST) WFC3+Spitzer IRAC variability monitoring for the highly variable young (∼20 Myr) planetary-mass object PSO J318.5-22. Our simultaneous HST + Spitzer observations covered approximately two rotation periods with Spitzer and most of a rotation period with the HST. We derive a period of 8.6 ± 0.1 hr…

2018 The Astronomical Journal
eHST 59
SCExAO/CHARIS Near-infrared Direct Imaging, Spectroscopy, and Forward-Modeling of κ And b: A Likely Young, Low-gravity Superjovian Companion
DOI: 10.3847/1538-3881/aae9ea Bibcode: 2018AJ....156..291C

Currie, Thayne; Nielsen, Eric L.; Kwon, Jungmi +30 more

We present SCExAO/CHARIS high-contrast imaging/JHK integral field spectroscopy of κ And b, a directly imaged low-mass companion orbiting a nearby B9V star. We detect κ And b at a high signal-to-noise ratio and extract high-precision spectrophotometry using a new forward-modeling algorithm for (A-)LOCI complementary to KLIP-FM developed by Pueyo et…

2018 The Astronomical Journal
Gaia 56
A Robust Tip of the Red Giant Branch Distance to the Fireworks Galaxy (NGC 6946)
DOI: 10.3847/1538-3881/aad3b2 Bibcode: 2018AJ....156..105A

Anand, Gagandeep S.; Tully, R. Brent; Rizzi, Luca

Archival HST data taken in F606W+F814W of two different fields in the outer regions of NGC 6946 is used to measure a tip of the red giant branch distance to the galaxy. We employ a Bayesian maximum-likelihood modeling method that incorporates the completeness of the photometry, and allows us to model the luminosity function of the RGB population. …

2018 The Astronomical Journal
eHST 56
The California-Kepler Survey. VI. Kepler Multis and Singles Have Similar Planet and Stellar Properties Indicating a Common Origin
DOI: 10.3847/1538-3881/aae70a Bibcode: 2018AJ....156..254W

Fulton, Benjamin J.; Isaacson, Howard T.; Howard, Andrew W. +8 more

The California-Kepler Survey (CKS) catalog contains precise stellar and planetary properties for the Kepler planet candidates, including systems with multiple detected transiting planets (“multis”) and systems with just one detected transiting planet (“singles”, although additional planets could exist). We compared the stellar and planetary proper…

2018 The Astronomical Journal
Gaia 54
Hydrogen and Sodium Absorption in the Optical Transmission Spectrum of WASP-12b
DOI: 10.3847/1538-3881/aadca7 Bibcode: 2018AJ....156..154J

Cochran, William D.; Endl, Michael; Redfield, Seth +2 more

We have obtained >10 hr of medium-resolution (R ∼ 15,000) spectroscopic exposures on the transiting exoplanet host star WASP-12, including ∼2 hr while its planet, WASP-12b, is in transit, with the Hobby-Eberly Telescope. The out-of-transit and in-transit spectra are coadded into master out-of-transit and in-transit spectra, from which we create…

2018 The Astronomical Journal
Gaia 54