SAO: Symbiotic Stars
Posted: Mon Feb 22, 2010 5:34 pm
Symbiotic Stars
Smithsonian Astrophysical Observatory - 2010 Feb 19
Smithsonian Astrophysical Observatory - 2010 Feb 19
ImagesMany, perhaps even most stars, are members of binaries -- two stars that orbit each other. Symbiotic stars are a small subset of binaries with an attitude: they display characteristic, dramatic, episodic changes in the spectra of their light because (it is thought) one star of pair is a very hot, small star while the other is a cool giant. Cool giant stars are known to have winds. If material in the wind of a giant accretes onto the hot companion, the latter will erupt with bright emission in the visible and occasionally in X-rays. At least, this is what astronomers suspect is happening. Besides wanting to understand what powers these strangely variable objects, astronomers also want to understand how they are formed, and why more binary stars are not symbiotics.