Analysis of Photoelectric Light Curves of YY Sagitarii
Abstract
Yellow, blue, and unfiltered light curves of the apsidally-rotating close binary YY Sgr have been analyzed with a simple modeling code. A consistent light-curve representation has been attained although observational errors are large. Within a wide tolerance, a new unstandardized UV light curve is shown to be consistent with the others. The binary appears to have an unlikely UV excess. A few times of minimum light have been added to the historical timings but 50 percent of the apsidal rotation period has not yet been covered. The apsidal period is shown to be of the order of 325 yr and the stellar structure parameter, k2, has been evaluated on the basis of this period and an assumed stellar mass ratio. Its value does not disagree with modern theory.
- Publication:
-
The Astronomical Journal
- Pub Date:
- August 1992
- DOI:
- 10.1086/116274
- Bibcode:
- 1992AJ....104..796W
- Keywords:
-
- Astronomical Photometry;
- Binary Stars;
- Electrophotometers;
- Light Curve;
- Variable Stars;
- Stellar Evolution;
- Stellar Mass;
- Stellar Rotation;
- Astrophysics;
- BINARIES: CLOSE;
- BINARIES: VISUAL;
- BINARIES: ECLIPSING