Looking for more information on bipolar nebula. Are the central stars all binary stars? I have done the search thing and came back with a lot of nice pictures but no information.
From Wikipedia, the free encyclopedia
Bipolar planetary nebula PN Hb 12.
A bipolar nebula is a type of nebula characterized by two lobes either side of a central star. About 10-20% of planetary nebulae are bipolar.
Though the exact causes of this nebular structure are not known, it is often thought to imply the presence of a binary central star with a period of a few days to a few years. As one of the two stars expelled its outer layers, the other disrupted the outflow of material to form the bipolar shape..