A Spectroscopic Study of Kepler Asteroseismic Targets

TL;DR

This study provides spectroscopic data for Kepler asteroseismic target candidates, revealing stellar parameters and binary status, including the discovery of new binary systems and confirmation of known variables.

Contribution

It offers detailed spectroscopic analysis and orbital solutions for several Kepler target stars, including the identification of new binary systems and variable stars.

Findings

Three stars show variable radial velocities.

Orbital elements for two binary systems are derived.

HIP 94743 identified as a detached eclipsing binary.

Abstract

Reported are spectroscopic observations of 15 candidates for Kepler primary asteroseismic targets and 14 other stars in the Kepler field, carried out at three observatories (see the footnote). For all these stars, the radial velocities, effective temperature, surface gravity, metallicity, and the projected rotational velocity are derived from two separate sets of data by means of two independent methods. In addition, MK type is estimated from one of these sets of data. Three stars, HIP 94335, HIP 94734, and HIP 94743, are found to have variable radial-velocity. For HIP 94335 = FL Lyr, a well-known Algol-type eclipsing variable and a double-lined spectroscopic binary, the orbital elements computed from our data agree closely with those of Popper et al. For HIP 94734 and HIP 94743 = V2077 Cyg, which we discover to be single-lined systems, orbital elements are derived. In addition, from our value of the orbital period and the Hipparcos epoch photometry, HIP 94743 is demonstrated to be a detached eclipsing binary.