Fundamental Astrophysics from Precision Asteroseismology

University Of Texas At Austin, Austin TX

Investigators

Abstract

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). Dr. Michael Montgomery of the University of Texas will lead a combined observational and theoretical project to study pulsating white dwarf stars. They will use the Argos time-series photometer on the 2.1m at McDonald Observatory, supplemented by the 4.1m SOAR telescope in Chile, the 1.2m telescope at McDonald Observatory, and the CTAS 0.6m telescope in central Texas. New data will be analyzed to address fundamental astrophysical problems in three broad areas. First, they will model the detailed shapes of individual light curves to constrain the physics of turbulent heat transport (convection). This part of the project will employ supercomputer hydrodynamical simulations of convection. Second, they will measure the change in pulsation period due to cooling, which will place constraints on the stars' axion emission. Axions are candidates for dark matter particles, so the development and application of this technique might provide new tests of the cosmological significance of axions. Third, they will continue their observations and analysis of the recently-discovered new class of variable star, the hot DQV carbon-atmosphere white dwarfs. Currently, there are three known members of this class. Two of these stars contain a strong magnetic field, making them ideal targets for studying the interplay of pulsation, convection, and magnetic fields. This group will continue to develop content for the Freshman Research Initiative program at UT-Austin, which will involve freshmen and sophomore science majors in cutting-edge science. As in recent years, high school students will participate in observing runs, and three high school teachers have joined this group to assist in observing and learn the scientific method first hand. The team is broadening this participation through a program whereby small groups of high school students spend entire nights at lock-ins at their high school; they are electronically linked to the observations being taken at McDonald Observatory through the Argos Online website and can teleconference with the astronomers in the dome. In addition, they have an active collaboration with the Central Texas Astronomical Society. As part of this project, they will develop a database of observations accessible via a web interface. This archive will allow rapid searching of the observations, and will be made freely available to the community.