Paper: astro-ph/0510150
Date: Wed, 5 Oct 2005 20:35:39 GMT (163kb)

Title: Identifying Very Metal-Rich Stars with Low-Resolution Spectra:
Finding Planet-Search Targets

Authors: Sarah E. Robinson (1), Jay Strader (1), S. Mark Ammons (1), Gregory
Laughlin (1), and Debra Fischer (2) ((1) UCO/Lick Observatory, Department of
Astronomy and Astrophysics, University of California at Santa Cruz, (2)
Department of Physics and Astronomy, San Francisco State University)

Categories: astro-ph

Comments: Accepted for publication in the Astrophysical Journal
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We present empirical calibrations that estimate stellar metallicity,
effective temperature and surface gravity as a function of Lick/IDS indices.
These calibrations have been derived from a training set of 261 stars for which
(1) high-precision measurements of [Fe/H], T_eff and log g have been made using
spectral-synthesis analysis of HIRES spectra, and (2) Lick indices have also
been measured. Our [Fe/H] calibration, which has precision 0.07 dex, has
identified a number of bright (V < 9) metal-rich stars which are now being
screened for hot Jupiter-type planets. Using the Yonsei-Yale stellar models, we
show that the calibrations provide distance estimates accurate to 20% for
nearby stars.

This paper outlines the second tier of the screening of planet-search targets
by the N2K Consortium, a project designed to identify the stars most likely to
harbor extrasolar planets. Discoveries by the N2K Consortium include the
transiting hot Saturn HD 149026 b (Sato et al. 2005, astro-ph/0507009) and HD
88133 b (Fischer et al. 2005). See Ammons et al. (2005, In Press) for a
description of the first tier of N2K metallicity screening, calibrations using
broadband photometry.

\\ ( http://arXiv.org/abs/astro-ph/0510150 , 163kb)