Discovery of phase-locked variable polarization in an RS CVn like star, HR 5110.
Abstract
Using measurements on 79 nights in 1980 January-August, it is established that the polarization in the ultraviolet (U band) varies synchronously on the known binary period of 2.6132 days, with a peak-to-peak amplitude of 0.03%. The pattern is mainly second harmonic in character, as typical of binary star examples such as Algol and Upsilon Her. Reflection by the cooler star, by a plasma concentration, or both, is suggested. The scale of the polarization seems to be consistent with Rayleigh scattering by neutral hydrogen on the cooler star, and a roughly lambda to the -4th wavelength dependence should be searched for. The QU curve suggests a sizeable inclination for the system, of about 45 deg, but this is preliminary. Separately, a possible weak periodicity might be present on a subsidiary period, conceivably related to a rotating star spot.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- May 1981
- DOI:
- 10.1086/158912
- Bibcode:
- 1981ApJ...246..203B
- Keywords:
-
- Binary Stars;
- Late Stars;
- Optical Polarization;
- Stellar Radiation;
- Stellar Spectra;
- Ultraviolet Astronomy;
- Hydrogen;
- Neutral Gases;
- Power Spectra;
- Rayleigh Scattering;
- Stellar Temperature;
- Ultraviolet Spectra;
- Astronomy