Search Publications
Evidence for Atmospheric Cold-trap Processes in the Noninverted Emission Spectrum of Kepler-13Ab Using HST/WFC3
Madhusudhan, Nikku; Knutson, Heather A.; Wright, Jason T. +5 more
We observed two eclipses of the Kepler-13A planetary system, on UT 2014 April 28 and UT 2014 October 13, in the near-infrared using Wide Field Camera 3 on the Hubble Space Telescope. By using the nearby binary stars Kepler-13BC as a reference, we were able to create a differential light curve for Kepler-13A that had little of the systematics typic…
The SEEDS High-Contrast Imaging Survey of Exoplanets Around Young Stellar Objects
Henning, Thomas; Terada, Hiroshi; Usuda, Tomonori +49 more
We present high-contrast observations of 68 young stellar objects (YSOs) that have been explored as part of the Strategic Exploration of Exoplanets and Disks with Subaru (SEEDS) survey on the Subaru telescope. Our targets are very young (<10 Myr) stars, which often harbor protoplanetary disks where planets may be forming. We achieve a typical c…
Modeling the Historical Flux of Planetary Impactors
Nesvorný, David; Roig, Fernando; Bottke, William F.
The impact cratering record of the Moon and the terrestrial planets provides important clues about the formation and evolution of the solar system. Especially intriguing is the epoch ≃3.8-3.9 Gyr ago (Ga), known as the Late Heavy Bombardment (LHB), when the youngest lunar basins such as Imbrium and Orientale formed. The LHB was suggested to origin…
Different Origins or Different Evolutions? Decoding the Spectral Diversity Among C-type Asteroids
Jorda, L.; Lamy, P.; Groussin, O. +15 more
Anhydrous pyroxene-rich interplanetary dust particles (IDPs) have been proposed as surface analogs for about two-thirds of all C-complex asteroids. However, this suggestion appears to be inconsistent with the presence of hydrated silicates on the surfaces of some of these asteroids, including Ceres. Here, we report the presence of enstatite (pyrox…
The Solar Neighborhood. XXXIX. Parallax Results from the CTIOPI and NOFS Programs: 50 New Members of the 25 parsec White Dwarf Sample
Henry, Todd J.; Bergeron, P.; Lépine, Sébastien +9 more
We present 114 trigonometric parallaxes for 107 nearby white dwarf (WD) systems from both the Cerro Tololo Inter-American Observatory Parallax Investigation (CTIOPI) and the U. S. Naval Observatory Flagstaff Station (NOFS) parallax programs. Of these, 76 parallaxes for 69 systems were measured by the CTIOPI program and 38 parallaxes for as many sy…
An Updated 2017 Astrometric Solution for Betelgeuse
Kervella, P.; Decin, L.; Richards, A. M. S. +4 more
We provide an update for the astrometric solution for the Type II supernova progenitor Betelgeuse using the revised Hipparcos Intermediate Astrometric Data (HIAD) of van Leeuwen, combined with existing VLA and new e-MERLIN and ALMA positions. The 2007 Hipparcos refined abscissa measurements required the addition of so-called Cosmic Noise of 2.4 ma…
A Survey For Planetary-mass Brown Dwarfs in the Taurus and Perseus Star-forming Regions
Luhman, K. L.; Esplin, T. L.
We present the initial results from a survey for planetary-mass brown dwarfs in the Taurus star-forming region. We have identified brown dwarf candidates in Taurus using proper motions and photometry from several ground- and space-based facilities. Through spectroscopy of some of the more promising candidates, we have found 18 new members of Tauru…
NGC 1980 Is Not a Foreground Population of Orion: Spectroscopic Survey of Young Stars with Low Extinction in Orion A
Fang, Min; Pascucci, Ilaria; Wang, Hongchi +6 more
We perform a spectroscopic survey of the foreground population in Orion A with MMT/Hectospec. We use these data, along with archival spectroscopic data and photometric data, to derive spectral types, extinction values, and masses for 691 stars. Using the Spitzer Space Telescope data, we characterize the disk properties of these sources. We identif…
Large Magellanic Cloud Near-infrared Synoptic Survey. IV. Leavitt Laws for Type II Cepheid Variables
Macri, Lucas M.; Rejkuba, Marina; Ngeow, Chow-Choong +3 more
We present time-series observations of Population II Cepheids in the Large Magellanic Cloud at near-infrared (JHK s ) wavelengths. Our sample consists of 81 variables with accurate periods and optical (VI) magnitudes from the OGLE survey, covering various subtypes of pulsators (BL Herculis, W Virginis, and RV Tauri). We generate light-…
Binary Central Stars of Planetary Nebulae Discovered Through Photometric Variability. V. The Central Stars of HaTr 7 and ESO 330-9
Frew, David J.; Reindl, Nicole; Margheim, Steve +3 more
We find the central stars (CSs) of the planetary nebulae (PNe) HaTr 7 and ESO 330-9 to be close-binary systems. Both have orbital periods of less than half a day and contain an irradiated cool companion to the hot CS. We provide light curves, spectra, radial velocity curves, orbital periods, and binary modeling results for both systems. The binary…