Solar-like oscillations in the G2 subgiant beta Hydri from dual-site observations
Abstract
We have observed oscillations in the nearby G2 subgiant star beta Hyi using high-precision velocity observations obtained over more than a week with the HARPS and UCLES spectrographs. The oscillation frequencies show a regular comb structure, as expected for solar-like oscillations, but with several l=1 modes being strongly affected by avoided crossings. The data, combined with those we obtained five years earlier, allow us to identify 28 oscillation modes. By scaling the large frequency separation from the Sun, we measure the mean density of beta Hyi to an accuracy of 0.6%. The amplitudes of the oscillations are about 2.5 times solar and the mode lifetime is 2.3 d. A detailed comparison of the mixed l=1 modes with theoretical models should allow a precise estimate of the age of the star.
Cite
@article{arxiv.astro-ph/0703747,
title = {Solar-like oscillations in the G2 subgiant beta Hydri from dual-site observations},
author = {Timothy R. Bedding and Hans Kjeldsen and Torben Arentoft and Francois Bouchy and Jacob Brandbyge and Brendon J. Brewer and R. Paul Butler and Joergen Christensen-Dalsgaard and Thomas Dall and Soeren Frandsen and Christoffer Karoff and Laszlo L. Kiss and Mario J. P. F. G. Monteiro and Frank P. Pijpers and Teresa C. Teixeira and C. G. Tinney and Ivan K. Baldry and Fabien Carrier and Simon J. O'Toole},
journal= {arXiv preprint arXiv:astro-ph/0703747},
year = {2011}
}
Comments
13 pages, 14 figures, accepted by ApJ. Fixed minor typo (ref to Fig 14)