Luminosity change in DQ Herculis

Abstract

view Abstract Citations (23) References (12) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Luminosity change in DQ Herculis. Nelson, M. R. ; Olson, E. C. Abstract UBV photometry of DQ Her was obtained in 1975 in order to compare the light curves at the present epoch with those obtained in 1954. Near-IR and Stromgren-Crawford y light curves were also taken. It is found that since 1954, the B light outside eclipse has dimmed by about 0.5 magnitude and the light at primary minimum has dimmed by about 1.3 magnitudes. A simple analysis of the UBV light curves obtained in 1954 and 1975 reveals the occurrence of several light changes, providing indirect evidence that the mass-transfer rate is not constant with time. Specifically, it is shown that the nebula has fallen to about 25% of its 1954 luminosity while the accretion disk has fallen to 80% of its 1954 luminosity. It is concluded that variations in the mass-transfer rate of the order of 20% may occur on times scales of less than 0.7 yr, that much of the IR light at mideclipse may come from the red main-sequence star which eclipses the disk, and that the mass of the red star is no more than 0.4 solar mass. Publication: The Astrophysical Journal Pub Date: July 1976 DOI: 10.1086/154484 Bibcode: 1976ApJ...207..195N Keywords: Eclipsing Binary Stars; Hercules Nova; Light Curve; Stellar Luminosity; Stellar Spectrophotometry; Ubv Spectra; Mass Transfer; Near Infrared Radiation; Nebulae; Spectrum Analysis; Stellar Mass; Time Dependence; Astronomy full text sources ADS | data products SIMBAD (1)