Atmospheric parameters of red giants in the Kepler field

Details Atmospheric parameters of red giants in the Kepler field Atmospheric parameters of red giants in the Kepler field

2010-12-02

arxiv.org/abs/1012.0436v1

Astronomy and Astrophysics

Astrophysics

Solar and Stellar Astrophysics

6 pages, 4 figures, accepted by A&A

Scientific paper

Accurate fundamental parameters of stars are mandatory for the asteroseismic investigation of the Kepler mission to succeed. We will determine the atmospheric parameters for a sample of 6 well-studied bright K giants to confirm that our method produces reliable results. We then apply the same method to 14 K giants that are targets for the Kepler mission. We have used high-resolution, high signal-to-noise spectra from the FIES spectrograph on the Nordic Optical Telescope. We used the iterative spectral synthesis method VWA to derive the fundamental parameters from carefully selected high-quality iron lines and pressure-sensitive Calcium lines. We find good agreement with parameters from the literature for the 6 bright giants. We compared the spectroscopic values with parameters based on photometric indices in the Kepler Input Catalogue (KIC). We identify serious problems with the KIC values for [Fe/H] and find a large RMS scatter of 0.5 dex. The log g values in KIC agree reasonably well with the spectroscopic values with a scatter of 0.25 dex, when excluding two low-metallicity giants. The Teffs from VWA and KIC agree well with a scatter of about 85 K. We also find good agreement with log g and Teff derived from asteroseismic analyses for seven Kepler giant targets. We have determined accurate fundamental parameters of 14 giants using spectroscopic data. The large discrepancies between photometric and spectroscopic values of [Fe/H] emphasize the need for further detailed spectroscopic follow-up of the Kepler targets. This is mandatory to be able to produce reliable constraints for detailed asteroseismic analyses and for the interpretation of possible exo-planet candidates found around giant stars.

Affiliated with

Also associated with

No associations

Rating

Atmospheric parameters of red giants in the Kepler field does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Atmospheric parameters of red giants in the Kepler field, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Atmospheric parameters of red giants in the Kepler field will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-603763