Infrared Studies of Symbiotic Stars
Infrared photometry and spectroscopy of symbiotic stars is reviewed. It is shown that at wavelengths beyond lμm these systems are generally dominated by the cool star’s photosphere and, indeed, are indistinguishable from ordinary late-type giants. About 25% of symbiotic stars exhibit additional emission due to circumstellar dust. Most of the dusty systems probably involve Mira variables, the dust forming in the atmospheres of the Miras. In a few cases the dust is much cooler and the cool component hotter; the dust must then form in distant gas shielded from the hot component, perhaps by an acccretion disk.
Spectroscopy at 2μm can be used to spectral type the cool components, even in the presence of some dust emission. Distances may thereby be estimated, though with some uncertainty.
Spectroscopy at longer wavelengths reveals information about the dust itself. In most cases this dust appears to include silicate grains, which form in the oxygen-rich envelope of an M star. In the case of HD 330036, however, different emission features are found which suggest a carbon-rich environment.
KeywordsSpectral Type Dust Emission Monthly Notice Cool Star Cool Component
Unable to display preview. Download preview PDF.
- Allen, D.A.: 1974a, Inf. Bull. Var. Stars, 911.Google Scholar
- Allen, D.A.: 1979, Int. Astron. Union. Colloq. 46, pp.125–149.Google Scholar
- Allen, D.A.: 1981, Proc. N. Amer. Workshop Symbiotic Stars, in press.Google Scholar
- Bopp, B.W.: 1981, Proc. N. Amer. Workshop Symbiotic Stars, in press.Google Scholar
- Boyarchuk, A.A.: 1970, Chapter 3 in “Eruptive Stars”, Eds. Boyarchuk, A.A., and Gershberg, R.E., Academy of Sciences, Moscow.Google Scholar
- Carter, B.S., and Feast, M.W.: 1979, Inf. Bull. Var. Stars, 1714.Google Scholar
- Merrill, K.M.: 1977, Int. Astron. Union Circ., 3088.Google Scholar
- Neugebauer, G., and Leighton, R.B.: 1969, “Two micron sky survey”, NASA SP-3047.Google Scholar