Variability investigations of possible Maia stars.
Abstract
Series of spectrograms and a limited number of photometric measurements of selected early-type stars have been used to search in the measured radial velocities and light curves for stellar pulsations with timescales of a few hours. For these stars, located in the HR diagram between the β Cep and the δ Scu stars and designed sometimes as Maia variables, the presence of pulsations is claimed to be a common property. In our sample we found no hints for a general existence of such pulsations. RV-variations with the expected short-term scale could be observed for only two of the program stars, γ UMi and γ CrB. The variations are highly irregular in amplitude and frequency. On the other hand, for both stars a typical mean timescale of the RV-variation of about 2.4hr has been found which gives some hints to possibly common physical causes of short-term variations of stars in this part of the HR diagram. The RV-variation of γ CrB in the years 1992/93 could be attributed to a rotational splitting of nonradial pulsations.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- August 1995
- Bibcode:
- 1995A&A...300..783L
- Keywords:
-
- STARS: EARLY-TYPE;
- STARS: INDIVIDUAL: {GAMMA} UMI;
- {GAMMA} CRB;
- STARS: OSCILLATIONS;
- {DELTA} SCT