Extreme amplitude variations in 28 And
Abstract
New simultaneous observations using the four uvby filters of the Stroemgren photometric system have been collected in the year 1996 for the low amplitude delta Sct star 28 And. During the course of these observations, the observed amplitude of the light curves is very small as compared with any other data set available in the literature for this star. In particular, the actual amplitude is about 19 times less than during the last observing run, five years before. The frequency analysis of the data also reveals the existence of a secondary frequency nu _2. Hence, the monoperiodicity is not confirmed with the new data. In addition, the analysis of the phase shifts between observed light variations confirms the nonradial nature of the main pulsation of this star.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- October 1998
- Bibcode:
- 1998A&A...338..905R
- Keywords:
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- DELTA SCU;
- STARS: INDIVIDUAL: 28 AND;
- STARS: OSCILLATIONS;
- TECHNIQUES: PHOTOMETRIC