Photospheric metal abundances in active stellar atmospheres

Details Photospheric metal abundances in active stellar atmospheres Photospheric metal abundances in active stellar atmospheres

Oct 1998

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1998a%26a...338..661o&link_type=abstract

Astronomy and Astrophysics, v.338, p.661-673 (1998)

Astronomy and Astrophysics

Astrophysics

36

Stars: Abundances, Stars: Activity, Stars: Atmospheres, Stars: Fundamental Parameters, Stars: Individual: Rs Cvn Binaries

Scientific paper

With a sophisticated analysis we determine the photospheric metal abundances of active stars to investigate the abundance stratification in active stellar atmospheres. For selected single stars and RS CVn binaries we have taken high-resolution, high-SN and partially phase-resolved spectra of the entire visible range. With a purely spectroscopic, self-consistent method based on line profile synthesis and an equivalent width analysis, we derive the effective temperature Teff, surface gravity log g, microturbulence xi_t and the abundances of Fe, Mg and Si with high internal accuracy (Delta Teff =~ 70 K, Delta log g =~ 0.1 dex, Delta xi_t =~ 0.1 km/s, Delta [Fe/H], Delta [Mg/H], Delta [Si/H] =~ 0.05 dex). Stellar parameters and metal abundances are obtained for the single stars beta Cet, kappa Cet and pi (1) UMa as well as for the RS CVn binaries AY Cet, VY Ari, EI Eri, IM Peg, lambda And and II Peg. The effect of stellar activity features (spots and plages) on the derived parameters is investigated by phase-resolved spectroscopy; we find that one out of four systems shows a significant variation of the Mg and Si abundances with rotational phase. The results help solving the puzzle about the photospheric Fe abundances of RS CVn binaries; specifically, we obtain [Fe/H] >= -0.4 for all systems, indicating that they definitely are not metal-poor. In II Peg and lambda And, the metals are strongly depleted in the corona relative to the photosphere; in beta Cet and pi (1) UMa, Fe and Si are weakly depleted, but Mg is enhanced (with 1sigma significance). The abundance stratifications are discussed in terms of the FIP-effect and the hydrostatic equilibrium stratification.

Affiliated with

Also associated with

No associations

Rating

Photospheric metal abundances in active stellar atmospheres 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 Photospheric metal abundances in active stellar atmospheres, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Photospheric metal abundances in active stellar atmospheres will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1718248