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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Last changed: 2002/Jun/04
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