A Radial Velocity Search for p-Mode Pulsations in η Bootis
Abstract
The subgiant η Boo (G5 IV) has been reported to show p-mode pulsations, as evidenced by variations in the equivalent width of its hydrogen Balmer lines (reported by Kjeldsen et al.). In an attempt to confirm this report, we observed η Boo's radial velocity with the AFOE spectrograph for a total of 22 hours spread over seven successive nights in 1995 March. We find no evidence for the presence of excess power at the frequencies reported by Kjeldsen et al.; our upper limit corresponds to typical mode amplitudes of 0.5 m s-1, about 3 times smaller than the velocity amplitudes they inferred. Signals with amplitudes larger than 0.5 m s-1 may be present at other frequencies within the 0-1000 μHz range, but evidence for such signals is scanty, and typical mode amplitudes greater than 1.5 m s-1 are clearly inconsistent with our observations.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- January 1997
- DOI:
- 10.1086/303512
- Bibcode:
- 1997ApJ...475..322B
- Keywords:
-
- Stars: Individual: Constellation Name: η Bootis;
- Stars: Oscillations;
- Techniques: Radial Velocities