What magnitude to look for?

[lawsio]

Hi all,

First proper post on here so hello to all who don't read the welcome forum! Quick and pretty basic question to begin with;

What is the maximum magnitude objects should I be looking to find with my scope (Skyhawk 1145p). So far the faintest I've got is NGC457 at 6.5mag, which seemed OK with a 25mm eye piece, but how much fainter can I go? I read a lot on here from people asking similar questions however I know my scope isn't overly powerful so don't want to spend hours looking for something I'll never get anyway!

Also, I notice a lot on here have the 130p and ask similar questions (such as here http://stargazerslounge.com/beginners-help-advice/176935-good-nebula-see-130p.html). As the aperture on the 1145 isn't far off that of the 130 should I be paying attention to these too?

Thanks,

Ben

[lawsio]

Sorry to bump the thread but it dissapeared to page three before most got to read it!

Any advice?

[acey]

It really depends how dark your sky is. Also, when we speak of magnitude limit for deep-sky objects, we really mean small objects (i.e. ones of small angular size), where the total light of the object is the most important factor. With larger objects, surface brightness is the most important thing: you could have a large object of magnitude 6 (theoretically naked eye) but invisible with any telescope, if its surface brightness was too low in comparison with the sky itself.

Also note that clusters (like NGC457) are different from continuous objects (galaxies and nebulae). Increasing magnification will improve the visibility of point sources (e.g. stars in clusters) but may make continuous objects disappear from view.

With a 4" telescope at a dark site you should expect to be able to see galaxies down to about magnitude 11. At a light polluted site you might not be able to see any at all.

[hemihaggis]

ditto what acey said !!!

try this also http://stargazerslounge.com/beginners-help-advice/173511-list-challenges-newbies-through-old-hats.html

[lawsio]

Thanks for the advice both. I have had a look at the HAS challenges which is party why I asked the question - I don't want to disappoint myself by attempting to find ones I'm not going to see until the inevitable upgrade!

[hemihaggis]

i think the bronze challenge would a fair one for your scope ..

where are you observing from ...

[lawsio]

South Birmingham. I get fair views of the main stuff from my garden but the best I've had so far is out at Clent Hill - still not really a dark site but it's better than nothing.