Fine Grid Asteroseismology of G117-B15A and R548
Abstract
We now have a good measurement of the cooling rate of G117-B15A. In the near future, we will have equally well determined cooling rates for other pulsating white dwarfs, including R548. The ability to measure their cooling rates offers us a unique way to study weakly interacting particles that would contribute to their cooling. Working toward that goal, we perform a careful asteroseismological analysis of G117-B15A and R548. We study them side by side because they have similar observed properties. We carry out a systematic, fine grid search for best-fit models to the observed period spectra of those stars. We freely vary four parameters: the effective temperature, the stellar mass, the helium layer mass, and the hydrogen layer mass. We identify and quantify a number of uncertainties associated with our models. Based on the results of that analysis and fits to the periods observed in R548 and G117-B15A, we clearly define the regions of the four-dimensional parameter space occupied by the best-fit models.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- March 2008
- DOI:
- 10.1086/527287
- arXiv:
- arXiv:0711.2039
- Bibcode:
- 2008ApJ...675.1505B
- Keywords:
-
- dense matter;
- stars: oscillations;
- stars: variables: other;
- white dwarfs;
- Astrophysics
- E-Print:
- The first author would love to hear from you if you found this paper interesting. email agnes@astro.as.utexas.edu