Search for Evolutionary Changes in the Periods of Cepheids: BG Cru
Abstract
For the low-amplitude Cepheid BG Cru we have constructed an O - C diagram spanning a time interval 118 years. The O - C diagram has the shape of a parabola, which has made it possible to determine for the first time the quadratic light elements and to calculate the rate of evolutionary decrease in the period, dP/dt = -0.0787 (±0.0230) s yr-1. This points to the second crossing of the instability strip. The pulsation stability test proposed by Lombard and Koen (1993) confirms that the period decrease is real.
- Publication:
-
Astronomy Letters
- Pub Date:
- July 2019
- DOI:
- 10.1134/S1063773719070028
- Bibcode:
- 2019AstL...45..445B
- Keywords:
-
- Cepheids;
- period variability;
- stellar evolution