Effective Temperature, Radius, and Gravitational Redshift of Sirius B

Analysis of the Ha and line profiles in Sirius B, along with the apparent magnitude and parallax, yields Teff = 32000 + 1000 K, log g = 8.65, and R/R0 = 0.0078 1 0.0002. These values put Sirius B on the mass-radius relation for degenerate configurations of helium. The measured gravitational redshift is 89 1 16 km s ', which is in excellent agreement with that predicted by the radius and gravity.