A photometric study of the recurrent nova WZ Sagittae at minimum light

Abstract

view Abstract Citations (132) References (35) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS A photometric study of the recurrent nova WZ Sagittae at minimum light. Robinson, E. L. ; Nather, R. E. ; Patterson, J. Abstract We have acquired a new set of high-speed photometric observations of the recurrent nova WZ Sge; using these observations, we develop a quantitative model for the system. WZ Sge is a binary system with an orbital period of and a separation of 3.2 x 1010 cm consisting of an unevolved star with a mass of 0.019 M0 orbiting a white dwarf with a mass of 0.38 M0. Mass is being transferred from the late-type star to the white dwarf in a stream through the inner Lagrangian point at a rate of 1 x 1016 g -i The transferred material forms an accretion disk with a radius of 9.7 x l0 cm around the white dwarf. The accretion disk is optically thick and is the sole source of the broad hydrogen absorption lines seen in the spectrum of WZ Sge. At the point where the stream of transferred material impacts the disk, a bright shock front ("bright spot") is formed. The spot has a radius of 1.0 x l0 cm and an effective temperature near 1.6 x l0 K, and contributes about 15% of the total optical luminosity of the system. In addition, we detect very stable rapid coherent oscillations in the light curve of WZ Sge with periods of 28.98 s and 27.87 s, making WZ Sge the first recurrent nova in which such oscillations have been found. On one occasion both oscillations were present simultaneously in the light curve, and we use this fact to conclude that the rapid oscillations must be pulsations, that the pulsations cannot be radial pulsations, and that the pulsations are probably nonradial g-mode pulsations. Subject headings: stars: binaries - stars: individual - stars: novae Publication: The Astrophysical Journal Pub Date: January 1978 DOI: 10.1086/155766 Bibcode: 1978ApJ...219..168R Keywords: Eclipsing Binary Stars; Novae; Stellar Models; Stellar Spectrophotometry; White Dwarf Stars; Astronomical Photometry; Light Curve; Mass Ratios; Orbital Elements; Astronomy; Close Binaries:Recurrent Novae; Light Curves:Recurrent Novae; Mass Exchange:Recurrent Novae; Photometry:Recurrent Novae; Recurrent Novae:White Dwarfs full text sources ADS | data products SIMBAD (2)