The quasi-Algol GW Ori: The nature of eclipses and estimation of the component masses
Abstract
Our photoelectric UBVR observations revealed regular dimmings of the T Tau star GW Ori with the period of the radial-velocity variations P = 242d, which was previously discovered by Mathieu et al. (1991). The Algol-like dimmings lasted for 0.1P. The periodic dimmings continued only from 1987 through 1992 and then disappeared. The eclipses resulted from the covering of the central star by the envelope of gas and dust that filled the Roche lobe of the companion during this period. Overall, accretion from the flat protoplanetary disk in 1987-1991 caused the system's V brightness to decline by 0.1. Based on this hypothesis, we obtained the parameters for the components of GW Ori. The central star has a mass of 3.3 M_solar, a radius of 7.5 R_solar, and T = 5600 K. The secondary component has a mass of 0.3 M_solar and a radius <1.0 R_solar. We discuss the conflicts between the derived parameters and the theory of gravitational contraction. The temperature and radius of the massive star are presumed to be related to the parameters of the circumstellar envelope produced by accretion from the outer disk.
- Publication:
-
Astronomy Letters
- Pub Date:
- July 1998
- Bibcode:
- 1998AstL...24..528S