NOAO >   Observing Info >   Approved Programs >   2011B-0095

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Proposal Information for 2011B-0095


PI: Judith Provencal, University of Delaware, jlp@udel.edu
Address: Dept. of Physics and Astronomy, 223 Sharp Laboratory, Newark, DE 19716, USA

CoI: Mike Montgomery, University of Texas
CoI: Mike Reed, Southwestern Missouri State
CoI: James Dalessio, University of Delaware
CoI: S. O. Kepler, Universidade Federal do Rio Grande do Sol
CoI: Andrez Baran, Southweatern Missouri State
CoI: Luciano Fraga, SOAR (Southern Astrophysical Research Telescope)

Title: The Empirical Determination of Convection in Pulsating White Dwarf Stars

Abstract: We propose high speed photometric observations of the hydrogen atmosphere white dwarf HS0507+0434B as part of a coordinated international campaign designed to determine the properties of convection in white dwarf atmospheres. Convection is one of the largest sources of theoretical uncertainty in our understanding of stellar physics. Asteroseismology has proven a powerful tool to attack this problem. White dwarf pulsations appear as local surface temperature variations, leading to local changes in the convection zone's depth and its ability to absorb/release energy. As the convection zone waxes and wanes, it modulates the local energy flux, leading to highly nonlinear light curves. We will use the observed nonlinearities in high precision light curves provided by SOAR, combined with accurate frequency, amplitude, and phase information provided by the Kitt Peak 2.1 m and the entire WET run to directly probe the nature of HS0507+0434B's convection zone.


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NOAO >   Observing Info >   Approved Programs >   2011B-0095

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