A STUDY OF VEGA: A RAPIDLY ROTATING POLE-ON STAR
- Department of Physics, University of Auckland, 65 Princess St., Auckland (New Zealand)
- Department of Physics and Astronomy, Brandon University, Brandon, MB R7A 6A9 (Canada)
Ultra-high signal-to-noise, high dispersion spectroscopy over the wavelength range lambdalambda4519-4535 shows Vega to be a rapidly rotating star with V{sub eq} of 211 km s{sup -1} seen almost pole-on. The analysis of five independent series of spectroscopic data is combined with analyses of the hydrogen lines, Hgamma, Hbeta, and Halpha, and the latest absolute continuum flux for Vega to yield the following results: Vsin i = 20.8 +- 0.2 km s{sup -1}, polar T{sub eff} = 10, 000 +- 30 K, polar log g = 4.04 +- 0.01 dex, V{sub eq} = 211 +- 4 km s{sup -1}, breakup fraction = 0.81 +- 0.02, microturbulence (xi{sub T}) = 1.0 +- 0.1 km s{sup -1}, macroturbulence (zeta) = 7.4 +- 0.5 km s{sup -1}, and an inclination i = 5.{sup 0}7 +- 0.{sup 0}1. The variations in T{sub eff} and log g over the photosphere total 1410 K and 0.26 dex, respectively, while the mean temperature is 9560 +- 30 K and log g is 3.95 +- 0.01 dex. Low level variations in the Ti II 4529 A profile are also illustrated.
- OSTI ID:
- 21394271
- Journal Information:
- Astrophysical Journal, Vol. 712, Issue 1; Other Information: DOI: 10.1088/0004-637X/712/1/250; ISSN 0004-637X
- Country of Publication:
- United States
- Language:
- English
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