A&A Supplement Series, Vol. 126, November II 1997, 21-30
Received October 9, 1996; accepted February 17, 1997
B. Nordström - R.P. Stefanik - D.W. Latham - J. Andersen
Send offprint request: B. Nordström (Danish address):
E-mail: birgitta@astro.ku.dk
Astronomical Observatory, Niels Bohr Institute for Astronomy,
Physics & Geophysics,
Juliane Maries Vej 30, DK - 2100 Copenhagen, Denmark
Harvard-Smithsonian Center for Astrophysics, 60 Garden Street,
Cambridge, MA 02138, U.S.A.
We present new radial and rotational velocities for 595 nearby early F dwarfs, based on digital spectra cross-correlated with individually optimised synthetic template spectra. The selection of optimum templates, the determination of rotational velocities, and the extraction of velocities from the blended spectra of double-lined spectroscopic binaries are discussed in some detail. We find 170 spectroscopic binaries in the sample and determine orbits for 18 double-lined and 2 single-lined binaries, including some spectroscopic triples. 73 stars are listed with too rapid rotation to yield useful radial velocities (i.e. v sin i > 120 km s-1). We discuss the binary frequency in the sample, and the influence of unrecognised binaries on the definition of clean metallicity groups of young F dwarfs and the determination of their kinematical properties.
keywords: methods: statistical -- techniques: radial velocities -- stars: binaries: spectroscopic -- stars: kinematics -- Galaxy: solar neighbourhood