Search Publications
Orbits for 18 Visual Binaries and Two Double-line Spectroscopic Binaries Observed with HRCAM on the CTIO SOAR 4 m Telescope, Using a New Bayesian Orbit Code Based on Markov Chain Monte Carlo
Mendez, Rene A.; Claveria, Ruben M.; Orchard, Marcos E. +1 more
We present orbital elements and mass sums for 18 visual binary stars of spectral types B to K (five of which are new orbits) with periods ranging from 20 to more than 500 yr. For two double-line spectroscopic binaries with no previous orbits, the individual component masses, using combined astrometric and radial velocity data, have a formal uncert…
The Pan-Pacific Planet Search. VII. The Most Eccentric Planet Orbiting a Giant Star
Marshall, J. P.; Mustill, A. J.; Kane, Stephen R. +9 more
Radial velocity observations from three instruments reveal the presence of a 4 MJup planet candidate orbiting the K giant HD 76920. HD 76920b has an orbital eccentricity of 0.856 ± 0.009, making it the most eccentric planet known to orbit an evolved star. There is no indication that HD 76920 has an unseen binary companion, suggesting a …
Ultra-short-period Planets in K2 with Companions: A Double Transiting System for EPIC 220674823
Baranec, Christoph; Cochran, William D.; Duev, Dmitry A. +10 more
Two transiting planets have been identified orbiting K2 target EPIC 220674823. One object is an ultra-short-period planet (USP) with a period of just 0.57 days (13.7 hr), while the other has a period of 13.3 days. Both planets are small, with the former having a radius of {R}{{p}1}=1.5 {R}\oplus and the latter {R}{{p
Near-IR Transmission Spectrum of HAT-P-32b using HST/WFC3
Tsiaras, A.; Morello, G.; Damiano, M. +2 more
We report here the analysis of the near-infrared transit spectrum of the hot Jupiter HAT-P-32b, which was recorded with the Wide Field Camera 3 (WFC3) on board the Hubble Space Telescope. HAT-P-32b is one of the most inflated exoplanets discovered, making it an excellent candidate for transit spectroscopic measurements. To obtain the transit spect…
A Survey for Planetary-mass Brown Dwarfs in the Chamaeleon I Star-forming Region
Luhman, K. L.; Faherty, J. K.; Esplin, T. L. +2 more
We have performed a search for planetary-mass brown dwarfs in the Chamaeleon I star-forming region using proper motions and photometry measured from optical and infrared images from the Spitzer Space Telescope, the Hubble Space Telescope, and ground-based facilities. Through near-IR spectroscopy at Gemini Observatory, we have confirmed six of the …
Simultaneous Mass Determination for Gravitationally Coupled Asteroids
Chesley, Steven R.; Baer, James
The conventional least-squares asteroid mass determination algorithm allows us to solve for the mass of a large subject asteroid that is perturbing the trajectory of a smaller test asteroid. However, this algorithm is necessarily a first approximation, ignoring the possibility that the subject asteroid may itself be perturbed by the test asteroid,…
Improved Point-source Detection in Crowded Fields Using Probabilistic Cataloging
Finkbeiner, Douglas P.; Daylan, Tansu; Portillo, Stephen K. N. +1 more
Cataloging is challenging in crowded fields because sources are extremely covariant with their neighbors and blending makes even the number of sources ambiguous. We present the first optical probabilistic catalog, cataloging a crowded (∼0.1 sources per pixel brighter than 22nd mag in F606W) Sloan Digital Sky Survey r-band image from M2. Probabilis…
Infrared Photometric Properties of 709 Candidate Stellar Bowshock Nebulae
Kobulnicky, Henry A.; Dixon, Don M.; Schurhammer, Danielle P. +4 more
Arcuate infrared nebulae are ubiquitous throughout the Galactic Plane and are candidates for partial shells, bubbles, or bowshocks produced by massive runaway stars. We tabulate infrared photometry for 709 such objects using images from the Spitzer Space Telescope, the Wide-field Infrared Explorer, and the Herschel Space Observatory (HSO). Of the …
Scattering Properties of the Venusian Clouds Observed by the UV Imager on board Akatsuki
Yamada, M.; Imamura, T.; Murakami, S. +6 more
We analyze the albedo of Venus obtained from the UV Imager on board Akatsuki. A relative global mean albedo over phase angle is used in this study, and we confirm the glory feature at 283 and 365 nm in the data acquired in 2016 May. We successfully simulate the observation using a radiative transfer model. Our results show that cloud aerosols of {…
Plasma Environment around Comet 67P/Churyumov-Gerasimenko at Perihelion: Model Comparison with Rosetta Data
Altwegg, K.; Goetz, C.; Goldstein, R. +6 more
The plasma environment near comet 67P/Churyumov-Gerasimenko (67P/CG) is dynamically affected by various factors, including the incident solar wind and outgassing from the nucleus. The Rosetta spacecraft MAGnetometer (MAG) instrument observations near perihelion showed crossing events into a magnetic field-free region at about 170 km from the nucle…