The stability of the frequency content of Delta Scuti stars: HD 16439, AZ CMi, HD 223480
Abstract
In the framework of the study of the pulsational behaviour of Delta Scuti stars, multicolour photometry of (previously) considered monoperiodic or double mode pulsators was undertaken. The frequency content of the light variation of SAO 4710=HD 16439=V663 Cas is clearly changing since a new frequency, not present in 1989, was observed in 1995; a slight decrease is also observed in the amplitude of the dominant term. The light curve of V663 Cas is now explained by three frequencies, but the residual noise probably hides other terms. SAO 231800=HD 223480=BF Phe is confirmed to be a monoperiodic Delta Scuti star, but comparing 1989 and 1993 photometric measurements a strong reduction in the b amplitude is observed; on the other hand, the V amplitude is stable in 1991 and 1993. The monoperiodic light curve of HR 2989=AZ CMi seems more stable, giving only slight hints that small changes occurred. The different photometric behaviours of these stars are discussed in a paper submitted for Astronomy and Astrophysics; a comparison with other monoperiodic pulsators Beta Cas, 28 And, Tau Peg) is also done.
- Publication:
-
Delta Scuti Star Newsletter
- Pub Date:
- September 1995
- Bibcode:
- 1995DSSN....9....6P