Discovery of two short-period eclipsing binaries with active components.
Abstract
We present high-precision UBV(RI)_c_ photometry as well as soft X-ray light curves for the visual triple system HD 9770 and the visual binary HD 195434, obtained at the European Southern Observatory and extracted from the ROSAT all-sky survey, respectively. The optical photometry revealed that in both systems one component is a very short-period eclipsing binary showing also BY Dra-type variability. We have computed accurate orbital periods, deduced approximate physical parameters, spectral classifications, distances and X-ray luminosities and identified which component of each visual system is responsible for the optical variability. Futhermore, we find that both systems are variable in X-rays, but no correlation with the optical variability is seen.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- April 1997
- Bibcode:
- 1997A&A...320..586C
- Keywords:
-
- STARS: ACTIVITY;
- STARS: LATE-TYPE;
- STARS: VARIABLES;
- BINARIES: ECLIPSING;
- X-RAYS: STARS;
- TECHNIQUES: PHOTOMETRY