Pulsational Mapping of Calcium Across the Surface of a White Dwarf
- Author(s)
- Susan Thompson, Michael H. Montgomery, Ted A. von Hippel, Atsuko Nitta, James Dalessio, Gerald Handler
- 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 themetals 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.
- Organisation(s)
- Department of Astrophysics
- External organisation(s)
- University of Delaware, University of Texas, Austin, Apache Point Observatory
- Journal
- The Astrophysical Journal: an international review of astronomy and astronomical physics
- Volume
- 714
- Pages
- 296-308
- No. of pages
- 13
- ISSN
- 0004-637X
- DOI
- https://doi.org/10.1088/0004-637X/714/1/296
- Publication date
- 2010
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 103004 Astrophysics
- Portal url
- https://ucrisportal.univie.ac.at/en/publications/d8cabcf3-3f61-4578-a71e-43d83813fbab