Classical Cepheid luminosities from binary companions

Abstract

view Abstract Citations (55) References (49) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Classical Cepheid Luminosities from Binary Companions Evans, Nancy Remage Abstract Luminosities for the classical Cepheids Eta Aql, W Sgr, and SU Cas are determined from IUE spectra of their binary companions. Spectral types of the companions are determined from the spectra by comparison with the spectra of standard stars. The absolute magnitude inferred from these spectral types is used to determine the absolute magnitude of the Cepheid, either directly or from the magnitude difference between the two stars. For the temperature range of the companions (A0 V), distinctions of a quarter of a spectral subclass can be made in the comparison between the companions and standard stars. The absolute magnitudes for Eta Aql and W Sgr agree well with the period-luminosity-color relation of Feast and Walker (1987). Random errors are estimated to be 0.3 mag. SU Cas, however, is overluminous for pulsation in the fundamental mode, implying that it is pulsating in an overtone. Publication: The Astrophysical Journal Pub Date: May 1991 DOI: 10.1086/170004 Bibcode: 1991ApJ...372..597E Keywords: Cepheid Variables; Companion Stars; Stellar Luminosity; Interstellar Extinction; Iue; Stellar Magnitude; Stellar Spectra; Astrophysics; STARS: CEPHEIDS; STARS: LUMINOSITIES; STARS: PULSATION; STARS: SPECTRAL CLASSIFICATION; STARS: VISUAL MULTIPLES; ULTRAVIOLET: SPECTRA full text sources ADS | data products SIMBAD (9) MAST (1) INES (1)