Search Publications
A SEA BASS on the Exoplanet HD 209458b
Morello, G.
We present here the first application of Stellar and Exoplanetary Atmospheres Bayesian Analysis Simultaneous Spectroscopy (SEA BASS) on real data sets. SEA BASS is a scheme that enables the simultaneous derivation of four-coefficient stellar limb-darkening profiles, transit depths, and orbital parameters from exoplanetary transits at multiple wave…
A Spectroscopic Survey of Field Red Horizontal-branch Stars
Casetti-Dinescu, Dana I.; Afşar, Melike; Sneden, Christopher +3 more
A metallicity, chemical composition, and kinematic survey has been conducted for a sample of 340 candidate field red horizontal-branch (RHB) stars. Spectra with high resolution and high signal-to-noise ratio were gathered with the McDonald Observatory 2.7 m Tull and the Hobby-Eberly Telescope echelle spectrographs, and were used to determine effec…
Chlorine Isotope Ratios in M Giants
Pilachowski, C. A.; Maas, Z. G.
We have measured the chlorine isotope ratio in six M giant stars using HCl 1-0 P8 features at 3.7 microns with R ∼ 50000 spectra from Phoenix on Gemini South. The average Cl isotope ratio for our sample of stars is 2.66 ± 0.58 and the range of measured Cl isotope ratios is 1.76 < 35Cl/37Cl < 3.42. The solar system meteo…
Probing the Hill Sphere of (486958) 2014 MU69: HST FGS Observations during the 2017 July 17 Stellar Occultation
Stern, S. Alan; Spencer, John R.; Buie, Marc W. +6 more
We observed the 2017 July 17 stellar occultation of HD 168233 by the Kuiper Belt Object (486958) 2014 MU69, the close flyby target of the extended New Horizons mission. Rather than capture a solid body occultation by the KBO itself, our program aimed to constrain the opacity of rings, moons, or other debris in the nearby environment. We…
A Chemical and Kinematical Analysis of the Intermediate-age Open Cluster IC 166 from APOGEE and Gaia DR2
Schultheis, M.; Minniti, D.; Mészáros, Sz. +26 more
IC 166 is an intermediate-age open cluster (OC) (∼1 Gyr) that lies in the transition zone of the metallicity gradient in the outer disk. Its location, combined with our very limited knowledge of its salient features, make it an interesting object of study. We present the first high-resolution spectroscopic and precise kinematical analysis of IC 16…
Characterizing K2 Candidate Planetary Systems Orbiting Low-mass Stars. III. A High Mass and Low Envelope Fraction for the Warm Neptune K2-55b
Gorjian, Varoujan; Knutson, Heather A.; Schlieder, Joshua E. +23 more
K2-55b is a Neptune-sized planet orbiting a K7 dwarf with a radius of {0.715}-0.040+0.043 {R}⊙ , a mass of 0.688 ± 0.069 {M}⊙ , and an effective temperature of {4300}-100+107 K. Having characterized the host star using near-infrared spectra obtained at IRTF/SpeX, we observed a trans…
A Study of the Hα Variability of Be Stars
Kjurkchieva, Diana P.; Dimitrov, Dinko P.; Ivanov, Emil I.
This paper presents the results of 4 years of high-resolution spectral observations of 69 emission-line stars, 54 of them being newly discovered sources. We classified the stars on the basis of their position in the two-color IR diagram and some additional criteria: shape and width of the Hα profile, presence of He lines, proper motion and paralla…
A Correction for IUE UV Flux Distributions from Comparisons with CALSPEC
Bianchi, Luciana; Bohlin, Ralph C.
A collection of spectral energy distributions (SEDs) is available in the Hubble Space Telescope (HST) CALSPEC database that is based on calculated model atmospheres for pure hydrogen white dwarfs (WDs). A much larger set (∼100,000) of UV SEDs covering the range (1150-3350 Å) with somewhat lower quality are available in the IUE database. IUE low-di…
The Solar Neighborhood. XLIII. Discovery of New Nearby Stars with µ < 0.″18 yr-1 (TINYMO Sample)
Henry, Todd J.; Winters, Jennifer G.; Jao, Wei-Chun +5 more
We have conducted a novel search of most of the southern sky for nearby red dwarfs having low proper motions, with specific emphasis on those with µ < 0.″18 yr-1, the lower cutoff of Luyten’s classic proper-motion catalog. We used a tightly constrained search of the SuperCOSMOS database and a suite of photometric distance relat…
Multiwavelength Ground and Space Observations of the Variable White Dwarf BOKS 53856: Nonuniform Metal Absorption in Dark Spots
Debes, John H.; Howell, Steve B.; Hoard, D. W. +3 more
We analyze extensive ground- and space-based ultraviolet-infrared observations of the variable white dwarf BOKS 53856. Photometry and spectroscopy were obtained from the Hubble Space Telescope, Spitzer Space Telescope, Kepler and Swift satellites, Palomar Observatory, and Kitt Peak National Observatory. Time series data spanning the entire four-ye…