Probable nonradial g-mode pulsation in early A-type stars
Abstract
Context: .
Aims: .Asteroseismology of early A-type stars could be a new tool to test stellar convection theories.
Methods: .A survey for line profile variability in early A-type stars has been performed in order to detect nonradial pulsation signatures.
Results: .The star HR 6139, with spectral type A2V and estimated T{eff}=8800 K, shows evident line profile variations that can be explained by oscillations in prograde g-modes. This feature and the known photometric variability are similar to those observed in the Slowly Pulsating B-type stars. However HR 6139 is much cooler than the cool border of the instability strip of such variables, and it is hotter than the blue edge of the δ Scuti instability strip. There are indications of a tiny variability also in other four objects, whose nature is not yet clear.
Conclusions: .
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- January 2006
- DOI:
- 10.1051/0004-6361:200500216
- arXiv:
- arXiv:astro-ph/0511491
- Bibcode:
- 2006A&A...445L..15A
- Keywords:
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- Astrophysics
- E-Print:
- 4 pages, 5 figures