Search Publications
Phosphorus Abundances in the Hyades and Galactic Disk
Cescutti, G.; Pilachowski, C. A.; Maas, Z. G.
We have measured phosphorus abundances in nine disk stars between -1 < [Fe/H] < -0.5 and in 12 members of the Hyades open cluster using two P I lines at 1.06 µm. High-resolution infrared spectra were obtained using Phoenix on Gemini South and abundances were determined by comparing synthetic spectra to the observations. The average abu…
Qatar Exoplanet Survey: Qatar-8b, 9b, and 10b—A Hot Saturn and Two Hot Jupiters
Bieryla, Allyson; Latham, David W.; Esquerdo, Gilbert A. +26 more
In this paper we present three new extrasolar planets from the Qatar Exoplanet Survey. Qatar-8b is a hot Saturn, with M P = 0.37 M J and R P = 1.3 R J, orbiting a solar-like star every P orb = 3.7 days. Qatar-9b is a hot Jupiter with a mass of M P = 1.2 M J and a radius o…
The Eclipsing δ Scuti Star EPIC 245932119
Kristiansen, Martti H.; Hong, Kyeongsoo; Lee, Jae Woo
We present the physical properties of EPIC 245932119 (K p = +9.82) exhibiting both eclipses and pulsations from the K2 photometry. The binary modeling indicates that the eclipsing system is in detached or semi-detached configurations with a mass ratio of 0.283 or 0.245, respectively, and that its light-curve parameters are almost unaffe…
The HD 181433 Planetary System: Dynamics and a New Orbital Solution
Kane, Stephen R.; Wittenmyer, Robert A.; Horner, Jonathan +7 more
We present a detailed analysis of the orbital stability of the HD 181433 planetary system, finding it to exhibit strong dynamical instability across a wide range of orbital eccentricities, semimajor axes, and mutual inclinations. We also analyze the behavior of an alternative system architecture, proposed by Campanella, and find that it offers gre…
Asteroseismology of the Multiplanet System K2-93
Vanderburg, Andrew; Chaplin, William J.; Davies, Guy R. +14 more
We revisit the analysis of the bright multiplanet system K2-93, discovered with data taken by the K2 mission. This system contains five identified planets ranging in size from sub-Neptune to Jupiter size. The K2 data available at the discovery of the system only showed single transits for the three outer planets, which allowed weak constraints to …
APOGEE/Kepler Overlap Yields Orbital Solutions for a Variety of Eclipsing Binaries
Stassun, Keivan G.; Agol, Eric; Rawls, Meredith L. +4 more
Spectroscopic eclipsing binaries (SEBs) are fundamental benchmarks in stellar astrophysics and today are observed in breathtaking detail by missions like the Transiting Exoplanet Survey Satellite (TESS), Kepler, and Apache Point Observatory Galactic Evolution Experiment (APOGEE). We develop a methodology for simultaneous analysis of high-precision…
OGLE-2015-BLG-1670Lb: A Cold Neptune beyond the Snow Line in the Provisional WFIRST Microlensing Survey Field
Han, Cheongho; Udalski, Andrzej; Lee, Chung-Uk +56 more
We present the analysis of the microlensing event OGLE-2015-BLG-1670, detected in a high-extinction field very close to the Galactic plane. Due to the dust extinction along the line of sight, this event was too faint to be detected before it reached the peak of magnification. The microlensing light-curve models indicate a high-magnification event …
MOA-bin-29b: A Microlensing Gas-giant Planet Orbiting a Low-mass Host Star
Soszyński, I.; Szymański, M. K.; Mróz, P. +34 more
We report the discovery of a gas-giant planet orbiting a low-mass host star in the microlensing event MOA-bin-29 that occurred in 2006. We find five degenerate solutions with the planet/host-star mass ratio of q ∼ 10-2. The Einstein radius crossing time of all models are relatively short (∼4-7 days), which indicates that the mass of hos…
Analysis of HST WFPC2 Observations of Centaur 29P/Schwassmann-Wachmann 1 while in Outburst to Place Constraints on the Nucleus’ Rotation State
Schambeau, Charles A.; Fernández, Yanga R.; Samarasinha, Nalin H. +2 more
We present analysis of Hubble Space Telescope observations of Centaur 29P/Schwassmann-Wachmann 1 (SW1) while in outburst to characterize the outburst coma and place constraints on the nucleus’ spin state. The observations consist of Wide Field and Planetary Camera 2 (WFPC2) images from Cycle 5, GO-5829 acquired on UT 1996 March 11.3 and 12.1, whic…
A Pluto-Charon Sonata: Dynamical Limits on the Masses of the Small Satellites
Kenyon, Scott J.; Bromley, Benjamin C.
During 2005-2012, images from Hubble Space Telescope (HST) revealed four moons orbiting Pluto-Charon. Although their orbits and geometric shapes are well-known, the 2σ uncertainties in the masses of the two largest satellites—Nix and Hydra—are comparable to their HST masses. Remarkably, gravitational n-body computer calculations of the long-term s…