Monday, July 1 - Session 2 - 16:00

Multicolour photometry for mode identification

M.D. Reed
Southwest Missouri State University
Department of Physics, Astronomy, and Material Science
Springfield,MO , USA

 

The goal of asteroseismology is to discern the physical conditions of stars by comparing observed pulsations with models. To obtain this goal, the observed pulsation periods and the spherical harmonics (n, , and m) need to match the theoretical model. Typically the most difficult part in this process is the identification of the pulsation modes in the observations.
Multicolour photometry is one method that has proven useful for identifying pulsation modes. By observing stars through various wavebands, effects such as limb darkening can be used to discern the pulsation modes. By comparing the amplitudes and phases in different filters, it is possible to determine the spherical harmonics.
This talk will emphasize the work of Watson (1988), which has since been applied to many different types of variable stars including  Scuti (Garrido, Garcia-Lobo, and Rodriguez, 1990),  Doradus (Breger, et al., 1997),  Cepheid (Cugier, Dziembowski, and Pamyatnykh, 1994), and EC 14026 (Koen, 1998) stars. I will also discuss the technique of summing spectra (especially UV) into various wavebands which are then used to identify modes as pioneered by Robinson, Kepler, and Nather (1982) and applied to white dwarf stars (Clemens, van Kerkwijk, and Wu, 2000; Kepler, et al., 2000).

 
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