1998/04/20 by J. B. Holberg, M. A. Barstow, F. C. Bruhweiler +2 · 1 citation
Physics and Astronomy · #Stellar, planetary, and galactic studies #Astrophysics and Star Formation Studies #Gamma-ray bursts and supernovae
paper · pdf · doi:10.1086/305489
openalex publication_date 1998/04/20 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/31
Long-standing questions regarding the temperature, gravity, mass, and radius of the well-known white dwarf Sirius B are considered in light of new data. Recently obtained Extreme Ultraviolet Explorer ( EUVE ) observations and reprocessed IUE NEWSIPS data have produced a new, well-defined effective temperature of 24,790 ± 100 K and a surface gravity of log g = 8.57 ± 0.06 for Sirius B. A new Hipparcos parallax for the Sirius system of π = 0 37921 ± 0 00158 is used in conjunction with the above spectroscopic results and the previously published gravitational redshift to yield a mass of 0.984 ± 0.074 M ☉ and a radius of R = 0.0084 ± 0.00025 R ☉ for the white dwarf. Combining these results with the existing astrometric mass for Sirius B gives a refined mass estimate of M = 1.034 ± 0.026 M ☉ . The mass and radius for Sirius B are found to be consistent with the theoretical mass-radius relation for a carbon-core white dwarf. The EUVE spectrum is also used to determine a firm upper limit of He/H = 1.8 × 10 -5 for the helium mixing ratio in the photosphere of Sirius B. IUE echelle spectra of Sirius B provide an estimate of log N H I = 17.72 ± 0.1 for the interstellar H I column to this star.