Search Publications
The N2K Consortium. IV. New Temperatures and Metallicities for More than 100,000 FGK Dwarfs
Strader, Jay; Laughlin, Gregory; Ammons, S. Mark +3 more
We have created specialized target lists for radial velocity surveys that are biased toward stars that (1) possess planets and (2) are easiest to observe with current detection techniques. We use a procedure that uniformly estimates fundamental stellar properties of Tycho 2 stars, with errors, using spline functions of broadband photometry and pro…
Two Suns in The Sky: Stellar Multiplicity in Exoplanet Systems
Henry, Todd J.; Mason, Brian D.; Jao, Wei-Chun +4 more
We present results of a reconnaissance for stellar companions to all 131 radial velocity-detected candidate extrasolar planetary systems known as of 2005 July 1. Common proper-motion companions were investigated using the multiepoch STScI Digitized Sky Surveys and confirmed by matching the trigonometric parallax distances of the primaries to compa…
The Eclipsing Binary V1061 Cygni: Confronting Stellar Evolution Models for Active and Inactive Solar-Type Stars
Torres, Guillermo; Lacy, Claud H.; Marschall, Laurence A. +2 more
We present spectroscopic and photometric observations of the eclipsing system V1061 Cyg (P=2.35 days). A third star is visible in the spectrum, and the system is a hierarchical triple. We combine the radial velocities for the three stars, times of eclipse, and intermediate astrometric data from the Hipparcos mission (abscissa residuals) to establi…
First Results from the CHARA Array. III. Oblateness, Rotational Velocity, and Gravity Darkening of Alderamin
Ciardi, D. R.; Berger, D. H.; Goldfinger, P. J. +10 more
We present observations of the A7 IV-V star Alderamin (α Cep, HR 8162, HD 203280) from the Georgia State University CHARA Array. These infrared interferometric angular size measurements indicate a noncircular projected disk brightness distribution for this known rapid rotator. The interferometric observations are modeled as arising from an elongat…
Permitted Oxygen Abundances and the Temperature Scale of Metal-poor Turnoff Stars
Meléndez, Jorge; Shchukina, Nataliya G.; Vasiljeva, Irina E. +1 more
We use high-quality VLT/UVES published data of the permitted O I triplet and Fe II lines to determine oxygen and iron abundances in unevolved (dwarfs, turnoff, subgiants) metal-poor halo stars. The calculations have been performed both in LTE and non-LTE (NLTE), employing effective temperatures obtained with the new infrared flux method (IRFM) tem…
Resolving the Dusty Circumstellar Structure of the Enigmatic Symbiotic Star CH Cygni with the MMT Adaptive Optics System
Bieging, John H.; Marengo, Massimo; Hoffmann, William F. +6 more
We imaged the symbiotic star CH Cyg and two PSF calibration stars using the unique 6.5 m MMT deformable secondary adaptive optics system. Our high-resolution (FWHM = 0.3"), very high Strehl (98%+/-2%), mid-infrared (9.8 and 11.7 µm) images of CH Cyg allow us to probe finer length scales than ever before for this object. CH Cyg is significant…