Stellar atmospheric parameters for the giant stars MU Pegasi and lambda Pegasi
Abstract
Profiles of the strong lines Ca II 8542 Angstroms, and Mg I 8806 Angstroms, together with regions containing Ca I, Fe I and Fe II lines in the spectra of the G8 giant stars mu Peg and lambda Peg have been recorded at high resolution and with signal/noise >= 100. The wings of the strong lines and the full profiles of intermediate strength lines are consistent with an LTE analysis based on the following sets of atmospheric parameters: star name star name mu Peg lambda Peg T_eff (K) 5000 \pm 50 4800 \pm 50 \log g (g in cm s^{-2}) 2.6 \pm 0.1 1.7 \pm 0.1 [M/H] -0.1 \pm 0.05 -0.1 \pm 0.05 Microturbulence, \xi(km s^{-1}) 1.4 \pm 0.1 1.8 \pm 0.2 Macroturbulence, \zeta(km s^{-1}) 3.00 \pm 0.13 7.6 \pm 0.5$ These results, together with Hipparcos parallaxes and recently published photometry, lead to estimates of luminosity, mass and radius. Inferred angular diameters are consistent with a well established empirical relationship but disagree with direct measurements by an interferometric technique.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- November 1998
- Bibcode:
- 1998A&A...339..531S
- Keywords:
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- STARS: FUNDAMENTAL PARAMETERS;
- STARS: INDIVIDUAL: MU PEG;
- STARS: INDIVIDUAL: LAMBDA PEG