Abstract

view Abstract Citations (30) References (11) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS An absorption line in the ultraviolet spectrum of 40 ERI B. Greenstein, J. L. Abstract Two excellent low-resolution spectra show an absorption line of equivalent width 3 A, near 1391 A, in the typical DA (hydrogen atmosphere) white dwarf 40 Eri B. The line is confirmed by a high-resolution spectrum and is the first seen in any DA star. Ultraviolet fluxes and the profile of Lyman-alpha confirm an effective temperature near 17,000 K. If the line is Si IV, it requires a temperature near 40,000 K. Unattractive possibilities are a hot circumstellar absorbing envelope dependent on accretion from companions, or formation at large optical depth in a transparent atmosphere with high Si/H. A suggestion that H2 should be considered leads to the possible interpretation as the (0, 5) transition of the Lyman band, formed at small optical depth. The band should be stronger in cooler DAs. Publication: The Astrophysical Journal Pub Date: October 1980 DOI: 10.1086/183367 Bibcode: 1980ApJ...241L..89G Keywords: Absorption Spectra; Abundance; Stellar Spectra; Ultraviolet Spectra; White Dwarf Stars; Hydrogen; Lyman Alpha Radiation; Molecular Gases; Stellar Spectrophotometry; Stellar Temperature; Astrophysics full text sources ADS | data products SIMBAD (3) MAST (1)

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