brightest objects ??

[hemihaggis]

hi folks , i have saw the messier and caldwell catolg ect , but is there a list of objects by brightness/mag , to help with viewing through small scopes ??

cheers

[acey]

I would suggest getting an atlas with a mag limit appropriate to your scope and sky, then working through the constellations. I started with the Collins Gem Stars which has stars down to mag 4.5 and marks DSOs visible with binos or a small scope:

Stars (Collins GEM): Amazon.co.uk: Ian Ridpath, Wil Tirion: Books

The stated magnitude of DSOs can be deceptive because usually it's the total (integrated) magnitude that is given, but if the object is large then that brightness is getting spread over a big area, so it has low "surface brightness" and can be much harder to see than you might expect. Opinions always vary as to whether one object is easier or harder than another - people in light-polluted areas can struggle to see M33 with any instrument while in a dark enough sky it can become naked-eye visible. Just give them a go and you'll see what's easy for you and what's hard. I would say, though, that the Caldwell list has a far bigger scale of difficulty than the Messier list - some of the Caldwells are really very challenging, while others (e.g. Double Cluster, Eskimo nebula) are showpiece objects.

Andrew