The Prospects for Asteroseismology from Ground-based Sites

Abstract

We reexamine the possibility of detecting p-mode oscillations in Sun-like stars with ground-based telescopes. Previous attempts to make such observations with photometric techniques have been limited to subgiant stars in M67 and have illustrated the great difficulties involved in performing ground-based asteroseismology. Substantial gains in observing efficiency can be realized from new diagnostic techniques and improvements in instrumentation, especially with new CCD camera systems. We show that for appropriately selected field stars observed with a network of telescopes or at a high-duty-cycle site, it will be possible to detect p-mode oscillations from the ground. An alternative to a network of telescopes for asteroseismology would be to develop a dedicated observatory for this purpose at a high-duty-cycle site, i.e., the South Pole. We estimate the scintillation, the main noise source in asteroseismology, at the Pole by modeling the index of refraction structure parameter from meteorological data. The model results show that at the Pole the variance of the relative intensity fluctuations-i.e., the scintillation-should be a factor of 5 smaller than at Mauna Kea. Taking into account the improvements possible with target selection and instrumentation, the South Pole would be an excellent site for asteroseismological work on Sun-like stars.