Hi, what really defines a double star?
http://www.youtube.com/watch?v=1L4Rre7v8a0
Are many doubles, gravitationally bound?
Is there a good resource about that can give me the distances between doubles.
I am more interested in doubles that are very close to each other and would love to find information on those targets.
I guess when viewing clusters as well...it would be good to know just how far these stars are from each other, as opposed to just enjoying the patterns in which we see them.
Having trouble getting the information, to keep me motivated. What other factors do you consider when gazing upon such targets...Spectral/color....???