Phase-dependent variations of H-alpha equivalent width in VW CEP

Abstract

view Abstract Citations (2) References (16) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Phase-Dependent Variations of Hα Equivalent Width in VW CEP Herbst, William ; Bishel, Lynn E. Abstract Hα photometry of the W UMa type eclipsing binary VW Cep has been obtained on four nights in 1985 at Van Vleck Observatory. A phase-dependent variation of Hα equivalent width (EW) has been discovered. The absorption EW decreases by a small (0.1 - 0.2 Å) but significant amount during both eclipses. No significant difference in the amplitude of the effect is seen between primary and secondary eclipse. The most likely interpretation is that the photospheric absorption-line EW decreases during eclipse. It is also possible that an emission component to the line is seen more prominently during both eclipses, resulting in a net decrease in the absorption EW. No evidence for plage-like concentrations of Hα flux on either component of the binary is found. Publication: The Astronomical Journal Pub Date: October 1987 DOI: 10.1086/114539 Bibcode: 1987AJ.....94.1051H Keywords: Astronomical Photometry; Eclipsing Binary Stars; H Alpha Line; Spectral Line Width; Absorption Spectra; Photosphere; Stellar Oscillations; Astrophysics; STARS: BINARIES; STARS: ECLIPSING BINARIES full text sources ADS | data products SIMBAD (2)