I recently went up form a 4 inch to 8 inch, and boy are there a lot of stars in the night sky. I particularly enamoured with globular clusters, and I have been spending lots of time with Omega Centauri/Caldwell 80 as it is nice and high form my vantage point.
Last night though, I tried my hand at M4 – it is the same Apparent magnitude and apparent size as C80 according to Stellarium. What I ended up seeing was something much smaller, but not necessarily fainter.
With C80, it sits comfortably in my 20mm eyepiece and if I swap in my 10mm it fills the entire field of view.
The object I observed list night was so small I ended up using my 10mm to observe it. Going back to my star chart I think it must have been NGC 6144, a 9.63 magnitude cluster….
I live in a city centre with a street light right next to me. Not ideal observing circumstances.
My question then, would it be possible for me to have seen the NGC 6144 cluster at that magnitude with an 8inch dob?
Would it not have been to faint at a magnitude of 9.63?
I am very confused/