Search Publications
The Effects of Stellar Companions on the Observed Transiting Exoplanet Radius Distribution
Howell, Steve B.; Hirsch, Lea A.; Ciardi, David R. +2 more
Understanding the distribution and occurrence rate of small planets was a fundamental goal of the Kepler transiting exoplanet mission, and could be improved with K2 and Transiting Exoplanet Survey Satellite (TESS). Deriving accurate exoplanetary radii requires accurate measurements of the host star radii and the planetary transit depths, including…
Medium-sized Satellites of Large Kuiper Belt Objects
Brown, Michael E.; Butler, Bryan J.
While satellites of mid- to small-Kuiper Belt objects tend to be similar in size and brightness to their primaries, the largest Kuiper Belt objects preferentially have satellites with small fractional brightness. In the two cases where the sizes and albedos of the small faint satellites have been measured, these satellites are seen to be small icy…
Subaru/HiCIAO HK s Imaging of LKHa 330: Multi-band Detection of the Gap and Spiral-like Structures
Henning, Thomas; Terada, Hiroshi; Usuda, Tomonori +56 more
We present H- and K s-bands observations of the LkHα 330 disk with a multi-band detection of the large gap and spiral-like structures. The morphology of the outer disk (r ∼ 0.″3) at PA = 0°-45° and PA° = 180-290° is likely density wave-induced spirals, and comparison between our observational results and simulations suggests a planet fo…
The HR 4796A Debris System: Discovery of Extensive Exo-ring Dust Material
Henning, Thomas; Debes, John H.; Schneider, Glenn +6 more
The optically and IR-bright and starlight-scattering HR 4796A ringlike debris disk is one of the most- (and best-) studied exoplanetary debris systems. The presence of a yet-undetected planet has been inferred (or suggested) from the narrow width and inner/outer truncation radii of its r = 1.″05 (77 au) debris ring. We present new, highly sensitiv…
Suppressed Far-UV Stellar Activity and Low Planetary Mass Loss in the WASP-18 System
France, K.; Fossati, L.; Lanza, A. F. +4 more
WASP-18 hosts a massive, very close-in Jupiter-like planet. Despite its young age (<1 Gyr), the star presents an anomalously low stellar activity level: the measured {log}{R}HK}{\prime } activity parameter lies slightly below the basal level; there is no significant time-variability in the {log}{R}HK}{\prim…
Absolute Properties of the Pulsating Post-mass Transfer Eclipsing Binary OO Draconis
Koo, Jae-Rim; Hong, Kyeongsoo; Lee, Jae Woo +1 more
OO Dra is a short-period Algol system with a δ Sct-like pulsator. We obtained time-series spectra between 2016 February and May to derive the fundamental parameters of the binary star and to study its evolutionary scenario. The radial velocity (RV) curves for both components were presented, and the effective temperature of the hotter and more mass…
The Rich Dynamics of Jupiter’s Great Red Spot from JunoCam: Juno Images
Hansen, C. J.; Bolton, S.; Hueso, R. +6 more
We have used high-resolution images obtained with JunoCam onboard the Juno spacecraft during its close flyby of Jupiter on 2017 July 11, to study the dynamics of the Great Red Spot (GRS) at the upper cloud level. We have measured the horizontal velocity and vorticity fields using the clouds as tracers of the flow. We have analyzed a variety of clo…
The Absolute Reflectance and New Calibration Site of the Moon
Lu, Yu; Cai, Wei; Wu, Yunzhao +1 more
How bright the Moon is forms a simple but fundamental and important question. Although numerous efforts have been made to answer this question such as use of sophisticated electro-optical measurements and suggestions for calibration sites, the answer is still debated. An in situ measurement with a calibration panel on the surface of the Moon is cr…
Optical Studies of 15 Hard X-Ray Selected Cataclysmic Binaries
Thorstensen, John R.; Halpern, Jules P.; Buckley, David A. H. +5 more
We conducted time-resolved optical spectroscopy and/or time-series photometry of 15 cataclysmic binaries that were discovered in hard X-ray surveys by the Swift Burst Alert Telescope and the International Gamma-Ray Astrophysics Laboratory, with the goal of measuring their orbital periods and searching for spin periods. Four of the objects in this …
A Comparative Study of WASP-67 b and HAT-P-38 b from WFC3 Data
Deming, Drake; Stevenson, Kevin B.; Wakeford, Hannah R. +12 more
Atmospheric temperature and planetary gravity are thought to be the main parameters affecting cloud formation in giant exoplanet atmospheres. Recent attempts to understand cloud formation have explored wide regions of the equilibrium temperature-gravity parameter space. In this study, we instead compare the case of two giant planets with nearly id…