Search Publications
The Second US Naval Observatory CCD Astrograph Catalog (UCAC2)
Zacharias, N.; Urban, S. E.; Wycoff, G. L. +4 more
The second US Naval Observatory (USNO) CCD Astrograph Catalog, UCAC2 was released in 2003 July. Positions and proper motions for 48,330,571 sources (mostly stars) are available on 3 CDs, supplemented with Two Micron All Sky Survey photometry for 99.5% of the sources. The catalog covers the sky area from -90° to +40° declination, going up to +52° i…
Do We Know of Any Maunder Minimum Stars?
Wright, J. T.
Most stars previously identified as Maunder minimum stars are old and evolved off the main sequence. Analysis of activity measurements from the California and Carnegie Planet Search program stars and Hipparcos parallaxes implies that the canonical relation between age and chromospheric activity breaks down for stars older than ~6 Gyr when activity…
Empirically Constrained Color-Temperature Relations. II. uvby
Grundahl, Frank; VandenBerg, Don A.; Bell, Roger A. +1 more
A new grid of theoretical color indices for the Strömgren uvby photometric system has been derived from MARCS model atmospheres and SSG synthetic spectra for cool dwarf and giant stars having -3.0<=[Fe/H]<=+0.5 and 3000<=Teff<=8000 K. At warmer temperatures (i.e., 8000<Teff<=40,000 K), this grid has been sup…
Speckle Observations of Binary Stars with the WIYN Telescope. IV. Differential Photometry
Horch, Elliott P.; van Altena, William F.; Meyer, Reed D.
Five hundred seventy-six magnitude difference measures are presented for 260 binary stars. These measures are derived from CCD-based speckle observations taken at the WIYN 3.5 m telescope at Kitt Peak National Observatory during the period 1997-2000. Separations of the systems range from over 1" down to near the diffraction limit of the telescope.…
Radial Velocity Studies of Close Binary Stars. IX.
Rucinski, Slavek M.; Capobianco, Christopher C.; DeBond, Heide +8 more
Radial velocity measurements and sine-curve fits to the orbital velocity variations are presented for the eighth set of 10 close binary systems: AB And, V402 Aur, V445 Cep, V2082 Cyg, BX Dra, V918 Her, V502 Oph, V1363 Ori, KP Peg, and V335 Peg. Half of the systems (V445 Cep, V2082 Cyg, V918 Her, V1363 Ori, and V335 Peg) were discovered photometric…
The Southern Proper Motion Program. III. A Near-Complete Catalog to V=17.5
Girard, Terrence M.; van Altena, William F.; López, Carlos E. +3 more
We present the third installment of the Yale/San Juan Southern Proper Motion Catalog, SPM3. Absolute proper motions, positions, and photographic BV photometry are given for roughly 10.7 million objects, primarily stars, down to a magnitude of V=17.5. The catalog covers an irregular area of 3700 deg2, between the declinations of -20° and…
Lick Northern Proper Motion Program. III. Lick NPM2 Catalog
Monet, David G.; Hanson, Robert B.; Jones, Burton F. +1 more
The Lick Northern Proper Motion (NPM) program, a two-epoch (1947-1988) photographic survey of the northern two-thirds of the sky (δ>~-23deg), has measured absolute proper motions, on an inertial system defined by distant galaxies, for 378,360 stars in the magnitude range 8<~B<~18. The 1993 NPM1 Catalog contains 148,940 stars in…
WIYN Open Cluster Study. XIX. Main-Sequence-Fitting Distances to Open Clusters Using V-K Color-Magnitude Diagrams
Sarajedini, Ata; Brandt, Ken; Grocholski, Aaron J. +1 more
We have combined existing optical magnitudes for stars in seven open clusters and 54 field stars with the corresponding JHKs photometry from the Two Micron All Sky Survey (2MASS). Combining optical with near-IR photometry broadens the color baseline, minimizing the influence of photometric errors and allowing better discrimination betwe…
New and Confirmed Triple Systems with Luminous Cool Primaries and Hot Companions
Parsons, Sidney B.
In the course of comparing parameters of evolved cool star plus hot main-sequence star binaries with theoretical isochrones, some discrepancies are found between implied stellar masses and the spectroscopic binary mass function or the measured angular separation. These are naturally explained if there is a third star in the system. Multiplicity is…
Synthetic Spectral Analysis of the Hot Component in the S-Type Symbiotic Variable EG Andromedae
Sion, Edward M.; Mikołajewska, Joanna; Kolb, Kelly +1 more
We have applied grids of non-LTE (NLTE) high-gravity model atmospheres and optically thick accretion disk models for the first time to archival IUE and FUSE spectra of the S-type symbiotic variable EG Andromedae taken at superior spectroscopic conjunction, when Rayleigh scattering should be minimal and the hot component is viewed in front of the r…