Abundances in Stars from the Red Giant Branch Tip to Near the Main-Sequence Turnoff in M71. I. Sample Selection, Observing Strategy, and Stellar Parameters
We present the sample for an abundance analysis of 25 members of M71, with luminosities ranging from the red giant branch tip to the upper main sequence. The spectra are of high dispersion and of high precision. We describe the observing strategy and determine the stellar parameters for the sample stars using both broadband colors and fits of Hα profiles. The derived stellar parameters agree with those from the Yale^2 stellar evolutionary tracks to within 50–100 K for a fixed log g, which is within the level of the uncertainties.
Additional Information© 2001 The American Astronomical Society. Received 2001 March 29; accepted 2001 May 18. Based on observations obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation. The entire Keck/HIRES and LRIS user community owes a huge debt to Jerry Nelson, Gerry Smith, Steve Vogt, Bev Oke, and many other people who have worked to make the Keck Telescope and HIRES and LRIS a reality and to operate and maintain the Keck Observatory. We are grateful to the W. M. Keck Foundation for the vision to fund the construction of the W. M. Keck Observatory. We thank Peter Stetson for supplying his M71 photometry in easily accessible form and Peter Hauschildt for calculating a grid of Ha profiles for us. Partial support was provided to M. M. B. by a Theodore Dunham, Jr., grant for Research in Astronomy and by the National Science Foundation under grants AST-98 19614 to J. G. C. and AST-96 24680 to M. M. B.
Published - Cohen_2001_AJ_122_1420.pdf