Search Publications
Astrometric Calibration of the Sloan Digital Sky Survey
Hennessy, G. S.; Munn, Jeffrey A.; Ivezić, Željko +4 more
The astrometric calibration of the Sloan Digital Sky Survey is described. For point sources brighter than r~20, the astrometric accuracy is 45 mas rms per coordinate when reduced against the USNO CCD Astrograph Catalog and 75 mas rms when reduced against Tycho-2, with an additional 20-30 mas systematic error in both cases. The rms errors are domin…
Investigation of 131 Herbig Ae/Be Candidate Stars
Alencar, S. H. P.; Corradi, W. J. B.; Guimarães, M. M. +5 more
We present a new catalog of 108 Herbig Ae/Be candidate stars identified in the Pico dos Dias Survey, together with 19 previously known candidates and four objects selected from the IRAS Faint Source Catalog. These 131 stars were observed with low- and/or medium-resolution spectroscopy, and we complement these data with high-resolution spectra of 3…
Empirically Constrained Color-Temperature Relations. I. BV(RI)C
VandenBerg, Don A.; Clem, James L.
This investigation presents a set of transformations to Johnson B-V, Cousins V-R, and Cousins V-I, as well as bolometric corrections to V, for [Fe/H]=-3, -2, -1, -0.5, 0.0, and +0.3 and, in each case, values of logg from -0.5 to 5.0 for 3000 K<=Teff<=5500 K and from 2.0 to 5.0 for 6000 K<=Teff<=40,000 K. These tra…
Spectral Irradiance Calibration in the Infrared. XIII. ``Supertemplates'' and On-Orbit Calibrators for the SIRTF Infrared Array Camera
Megeath, S. T.; Stauffer, John; Cohen, Martin +2 more
We describe the technique that will be used to develop a set of on-orbit calibrators for the Infrared Array Camera (IRAC) and demonstrate the validity of the method for stars with spectral types either K0-M0 III or A0-A5 V. For application to SIRTF, the approach is intended to operate with all available optical, near-infrared (NIR), and mid-infrar…
The Tycho-2 Spectral Type Catalog
Egan, Michael P.; Kraemer, Kathleen E.; Price, Stephan D. +1 more
The Tycho-2 Catalogue contains positions, proper motions, and BT and VT magnitudes for approximately 2.5 million stars. We have obtained spectral types for 351,864 of the Tycho-2 stars by cross-referencing Tycho-2 to several catalogs containing spectral types, using the VizieR astronomical database. The positional matching re…
Stellar Kinematic Groups. II. A Reexamination of the Membership, Activity, and Age of the Ursa Major Group
Adelman, Saul J.; Soderblom, David R.; King, Jeremy R. +2 more
Utilizing Hipparcos parallaxes, original radial velocities and recent literature values, new Ca II H and K emission measurements, literature-based abundance estimates, and updated photometry (including recent resolved measurements of close doubles), we revisit the Ursa Major moving group membership status of some 220 stars to produce a final clean…
Spectroscopic Binaries, Velocity Jitter, and Rotation in Field Metal-poor Red Giant and Red Horizontal-Branch Stars
Latham, David W.; Stefanik, Robert P.; Morse, Jon A. +2 more
We summarize 2007 radial velocity measurements of 91 metal-poor field red giants. Excluding binary systems with orbital solutions, our coverage averages 13.7 yr per star, with a maximum of 18.0 yr. We report four significant findings. (1) Sixteen stars are found to be spectroscopic binaries, and we present orbital solutions for 14 of them. The spe…
Parent Stars of Extrasolar Planets. VII. New Abundance Analyses of 30 Systems
Suntzeff, Nicholas B.; Gonzalez, Guillermo; Laws, Chris +4 more
The results of new spectroscopic analyses of 30 stars with giant planet and/or brown dwarf companions are presented. Values for Teff and [Fe/H] are used in conjunction with Hipparcos data and Padua isochrones to derive masses, ages, and theoretical surface gravities. These new data are combined with spectroscopic and photometric metalli…
Radial Velocity Studies of Close Binary Stars. VIII.
Rucinski, Slavek M.; Capobianco, Christopher C.; Lu, Wenxian +7 more
Radial velocity measurements and sine-curve fits to the orbital velocity variations are presented for the seventh set of 10 close binary systems: V410 Aur, V523 Cas, QW Gem, V921 Her, V2357 Oph, V1130 Tau, HN UMa, HX UMa, HD 93917, and NSV 223. All systems but three (V523 Cas, HD 93917, NSV 223) were discovered photometrically by the Hipparcos mis…
The Araucaria Project: Dependence of Mean K, J, and I Absolute Magnitudes of Red Clump Stars on Metallicity and Age
Udalski, A.; Gieren, W.; Pietrzyński, G.
As a part of our ongoing Araucaria Project on the improvement of stellar distance indicators we present deep near-infrared JK imaging of several fields in four Local Group galaxies: LMC, SMC, and the Carina and Fornax dwarf galaxies. These data were obtained under excellent seeing conditions at the European Southern Observatory Very Large Telescop…