I like to search out double stars and there is only one in the Messier catalogue and I have no idea how many are in the New General Catalogue. I bought the Cambridge Double Star Atlas that was made for the amateur astronomer in mind and it deletes binary systems that need an Observatory size telescope to find. It not only has a good summary of multiple star systems and how to tell a real binary from an optical double that many old catalogues have listed, it also has an excellent Star Atlas with details down to 8 magnitude stars. Most star atlas' do not usually go past 6 or 7 magnitude. This CDSC goes down to 7.75 double stars with the secondary down to 13 magnitude so a 6 inch telescope is needed for about 20% of the listed stars.
![Journey to the Andromeda Galaxy [4K]](http://i.ytimg.com/vi/-ybiXR2WCFQ/mqdefault.jpg)
I like to search out double stars and there is only one in the Messier catalogue and I have no idea how many are in the New General Catalogue. I bought the Cambridge Double Star Atlas that was made for the amateur astronomer in mind and it deletes binary systems that need an Observatory size telescope to find. It not only has a good summary of multiple star systems and how to tell a real binary from an optical double that many old catalogues have listed, it also has an excellent Star Atlas with details down to 8 magnitude stars.
Most star atlas' do not usually go past 6 or 7 magnitude. This CDSC goes down to 7.75 double stars with the secondary down to 13 magnitude so a 6 inch telescope is needed for about 20% of the listed stars.