Abundance analysis of targets for the COROT/MONS asteroseismology missions

Abstract

Abstract.One of the goals of the ground-based support program for the  and / satellite missions is to characterize suitable target stars for the part of the missions dedicated to asteroseismology. We present the detailed abundance analysis of nine of the potential  main targets using the semi-automatic software . For two additional  targets we could not perform the analysis due to the high rotational velocity of these stars. For five stars with low rotational velocity we have also performed abundance analysis by a classical equivalent width method in order to test the reliability of the  software. The agreement between the different methods is good. We find that it is necessary to measure abundances extracted from each line relative to the abundances found from a spectrum of the Sun in order to remove systematic errors. We have constrained the global atmospheric parameters T eff , log g, and [Fe/H] to within 70−100 K, 0.1−0.2 dex, and 0.1 dex for five stars which are slow rotators (v sin i < 15 km s −1 ). For most of the stars we find good agreement with the parameters found from line depth ratios, H α lines, Strömgren indices, previous spectroscopic studies, and also log g determined from the  parallaxes. For the fast rotators (v sin i > 60 km s −1 ) it is not possible to constrain the atmospheric parameters.

Binarity, activity and metallicity among late-type stars

“…The method is the same as employed by Dall et al (2005), adopted from the procedures of Morel et al (2003) and Bruntt et al (2002Bruntt et al ( , 2004. The first step is the measurement of the EWs, which is accomplished using DAOSPEC 1 (Stetson & Pancino 2005, in preparation), which uses an iterative Gaussian fitting and subtraction procedure to fit the lines and the effective continuum.…”

“…The software is called VWA which has a graphical user interface (GUI). The method and the VWA software have been described in detail by Bruntt et al (2002Bruntt et al ( , 2004 and the method compared to the classical EW method by Bikmaev et al (2002). The abundance analysis relies on atomic parameters from the VALD database (Kupka et al 1999;Piskunov et al 1995) and uses modified ATLAS9 atmospheric models from interpolation in the grid published by Heiter et al (2002).…”

A transiting giant planet with a temperature between 250 K and 430 K

“…* These values take into account the eccentricity as found by the radial-velocity observations. { These values are based on high-resolution (R < 65,000) spectra taken on 21 and 22 September 2008 with the ESO VLT/UVES in Dic1 mode (390 1 580), a slit width of 0.7 arcsec and analysis with the VWA software 18,19 . The planet's quoted period was determined from the first transit observed by CoRoT and from ground-based photometry of a transit on 5 September 2009, taken with the Euler 1.2 m telescope from La Silla, Chile, and the 2 m LCOGT Faulkes Telescope North at Haleakala Observatory.…”

Ground‐based follow‐up in relation to Kepler asteroseismic investigation

“…The second aim is to obtain more accurate photometric data, in Strömgren or Johnson passbands, to derive accurate values of log g, T eff , absolute magnitude, [M/H], and interstellar reddening (e.g. Bruntt et al 2004). …”