Pulsational Mapping of Calcium Across the Surface of a White Dwarf
Abstract
We constrain the distribution of calcium across the surface of the white dwarf star G29-38 by combining time series spectroscopy from Gemini-North with global time series photometry from the Whole Earth Telescope. G29-38 is actively accreting metals from a known debris disk. Since the metals sink significantly faster than they mix across the surface, any inhomogeneity in the accretion process will appear as an inhomogeneity of the metals on the surface of the star. We measure the flux amplitudes and the calcium equivalent width amplitudes for two large pulsations excited on G29-38 in 2008. The ratio of these amplitudes best fits a model for polar accretion of calcium and rules out equatorial accretion.
Keywords
Cite
@article{arxiv.1003.3374,
title = {Pulsational Mapping of Calcium Across the Surface of a White Dwarf},
author = {Susan E. Thompson and M. H. Montgomery and T. von Hippel and A. Nitta and J. Dalessio and J. Provencal and W. Strickland and J. A. Holtzman and A. Mukadam and D. Sullivan and T. Nagel and D. Koziel-Wierzbowska and S. Zola and T. Kundera and M. Winiarski and M. Drozdz and E. Kuligowska and W. Ogloza and Zs. Bognar and G. Handler and A. Kanaan and T. Ribeira and R. Rosen and D. Reichart and J. Haislip and B. N. Barlow and B. H. Dunlap and K. Ivarsen and A. LaCluyze and F. Mullally},
journal= {arXiv preprint arXiv:1003.3374},
year = {2015}
}
Comments
Accepted to the Astrophysical Journal. 16 pages, 10 figures.