AAS 203rd Meeting, January 2004
Session 43 Nearby Stars: Observations
Poster, Tuesday, January 6, 2004, 9:20am-6:30pm, Grand Hall

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[43.02] An Ongoing Program of Radial Velocities of Nearby Stars

J. Sperauskas (Vilnius University), R.P. Boyle (Vatican and Steward Observatories), J. Harlow (University of the Pacific), H. Jahreiss (Astronomisches Rechen-Institut), A.R. Upgren (Yale and Wesleyan Universities)

The lists of stars found by Vyssotsky at the McCormick Observatory and the Fourth Edition of the Catalog of Nearby Stars (CNS4) complement each other. Each was limited in a different way, but together they can be used to evaluate sources of systematic error in either of them. The lists of Vyssotsky comprise almost 900 stars, brighter than a limiting visual magnitude of about 11.5. and thus form a magnitude-limited sample. The CNS4 includes all stars believed to be within 25 parsecs of the Sun, and thus forms a distance-limited group. Limits in magnitude are prone to the Malmquist bias by which stars of a given range in magnitude may average spuriously brighter than stars within a given distance range appropriate for the mean distance modulus. The CNS4 stars may be subject to a slight Lutz-Kelker effect. This also requires a correction that depends mainly on the ratios of the standard errors in the distances to the stars, to the distances, themselves.

This is a status report on a survey seeking completeness in the six dynamical properties (positions along the three orthogonal axes, and their first time-derivatives). Parallax, proper motion and radial velocity are the stellar properties required for this information and, as is frequently the case among sets of faint stars, the radial velocities are not always available. We seek to obtain radial velocities for a full dynamical picture for more than one thousand nearby stars of which some two-thirds have been observed. It would be most desirable to follow with age-related measures for all stars

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Bulletin of the American Astronomical Society, 35#5
© 2003. The American Astronomical Soceity.