The cause of variablilty of HD 96008
Abstract
The evidence of a new class of F-type variable stars located on the cold border of the instability strip has been recently emphasized by many authors. Two alternative physical mechanisms are considered as responsible for such a variability: nonradial $g$ pulsation modes and stellar activity. In Issue 6 of Delta Scuti Newsletter, Krisciunas briefly reviewed the cases of 9 Aur and Gamma Dor; these two stars are more extensively discussed in two recent papers (9 Aur: Krisciunas et al., MNRAS, submitted; Gamma Dor: Balona et al., MNRAS 267, 103) and in both cases the respective authors suggest that nonradial g modes are the more plausible cause of variation. The cases of HD 224639 and HD 224945 are more complicated: Mantegazza et al. (1994, MNRAS 270, 439) found that the light curves of these two stars are rapidly changing in shape and that they are very difficult to fit even from a purely mathematical point of view. Maybe further observations will allow us to solve the matter. It should be noted that all the objects of this new class of variable stars have very similar uvby Beta indices.
- Publication:
-
Delta Scuti Star Newsletter
- Pub Date:
- January 1995
- Bibcode:
- 1995DSSN....8...13M