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Hydrocarbons, Ices, and “XCN” in the Line of Sight toward the Galactic Center

Published in The Astrophysical Journal

We discuss 2.8-3.9 μm spectra from the United Kingdom Infrared Telescope of seven sight lines toward IR sources near Sagittarius A* in the Galactic center (GC). In all lines of sight, the 3.0 μm H 2 O ice feature is present with optical depths in the range 0.33- 1.52. By constructing a simple ice model, we show that the ice profile is not fully acc...

The Molecular and Dust Envelope of HD 56126

Published in The Astrophysical Journal

HST/COS DETECTION OF THE SPECTRUM OF THE SUBDWARF COMPANION OF KOI-81Based on observations made with the NASA/ESA Hubble...

Published in The Astrophysical Journal

KOI-81 is a totally eclipsing binary discovered by the Kepler mission that consists of a rapidly rotating B-type star and a small, hot companion. The system was forged through large-scale mass transfer that stripped the mass donor of its envelope and spun up the mass gainer star. We present an analysis of UV spectra of KOI-81 that were obtained wit...

A class of eccentric binaries with dynamic tidal distortions discovered with Kepler

Published in The Astrophysical Journal

We have discovered a class of eccentric binary systems within the Kepler data archive that have dynamic tidal distortions and tidally induced pulsations. Each has a uniquely shaped light curve that is characterized by periodic brightening or variability at timescales of 4-20 days, frequently accompanied by shorter period oscillations. We can explai...

Outward migration of Jupiter and Saturn in evolved gaseous disks

Published in The Astrophysical Journal

The outward migration of a pair of resonant-orbit planets, driven by tidal interactions with a gas-dominated disk, is studied in the context of evolved solar nebula models. The planets masses, M 1 and M 2, correspond to those of Jupiter and Saturn. Hydrodynamical calculations in two and three dimensions are used to quantify the migration rates and...

Transit timing observations from Kepler. V. Transit timing variation candidates in the first sixteen months from polynom...

Published in The Astrophysical Journal

Transit timing variations provide a powerful tool for confirming and characterizing transiting planets, as well as detecting non-transiting planets. We report the results of an updated transit timing variation (TTV) analysis for 1481 planet candidates based on transit times measured during the first sixteen months of Kepler observations. We present...

Modeling Multi-wavelength Stellar Astrometry. II. Determining Absolute Inclinations, Gravity-darkening Coefficients, and...

Published in The Astrophysical Journal

Characterizing the purple Earth: Modelling the globally-integrated spectral variability of the Archean Earth

Published in The Astrophysical Journal

The MACHO Project Large Magellanic Cloud Variable-Star Inventory. IX. Frequency Analysis of the First-Overtone RR Lyrae ...

Published in The Astrophysical Journal

More than 1300 variables classified provisionally as first-overtone RR Lyrae pulsators in the MACHO variable-star database of the Large Magellanic Cloud (LMC) have been subjected to standard frequency analysis. Based on the remnant power in the prewhitened spectra, we found 70% of the total population to be monoperiodic. The remaining 30%(411 stars...

Transit timing observations from Kepler. IV. Confirmation of four multiple-planet systems by simple physical models

Published in The Astrophysical Journal

Eighty planetary systems of two or more planets are known to orbit stars other than the Sun. For most, the data can be sufficiently explained by non-interacting Keplerian orbits, so the dynamical interactions of these systems have not been observed. Here we present four sets of light curves from the Kepler spacecraft, each which of shows multiple p...