small telescope

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Peter Deedigan
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Joined: Mon Apr 22, 2013 10:44 am

small telescope

Post by Peter Deedigan » Mon May 20, 2013 5:15 pm

hi Lads,

Quick question. I have a limited view from where I am from about East to South roughly. I have been looking at a few Messier objects and they are faint at best. Saw M5 and M13 and they were faint and very vague (looked like a bit of cotton wool for all the world.)

I am using a 4" refractor in the city! Are all the Messier objects going to be this faint or is it a case of bad lighting and two bad examples? Are there other M objects that are better to see that I am just missing? I have seen star clustiers (M37 etc..) but tbh I am mad to see a galaxy (M31 is over the neighbours wall till winter I think!)

Have I any hope with 4" scope and bad lighting. Would it be the light pollution or the scope or both that are making them faint/vague?

Any/all suggestions welcome.

thanks,
Peter

Frank Ryan
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Joined: Sun Aug 05, 2007 2:45 am
Location: Ballycasey, Co. Clare

Post by Frank Ryan » Mon May 20, 2013 6:46 pm

Hi Peter.
Short answer is city lights are your enemy.
They will wreck any view bar the Moon & the planets.
A 4" refractor from a dark site will show more but
in terms of detail you need to go bigger to see 'brighter'.
Scopes are as good as thier light gathering power more so than magnification.
If your after Messier objects then consider buying at least a 10" Dobsonian.
(have you a link to the current scope you use?)
As for bright Messier objects. M42 is probably the best nebula & star cluster combined, M13 after that.
Messier objects as you describe well as "vague smudges"
just look like brighter vague smudges from a dark site. :-)

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Dave Lillis
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Joined: Sun Aug 05, 2007 10:02 am
Location: Limerick city

Post by Dave Lillis » Mon May 20, 2013 11:00 pm

Hey Peter,
If you want to look for a galaxy, you can always try M51, keep in mind that with a 4 inch refractor, all you'll see is a small fuzzy blob. The challenge isn't to eek out hubble space telescope views of these objects, the challenge is to find them and evaluate what you can see of them. Under a dark sky with dark adapted eyes and averted vision you might see a little more. Next time you look at a galaxy, remember that you are actually looking at something that's literally millions, sometimes 10s of millions of light years away, it puts abit of wonder into it. For m31, it's about 2 million light years. For M51 it's just over 23 million light years away.!

As for globular clusters, its more then just sky brightness tbh, light pollution dims them but doesn't really change what you see, if your scope cant resolve the cluster in a city, then it wont do it from a dark sky site either. You would see the fainter extremities of it from a dark site, and it would look overall brighter. As you increase the scopes aperture, they turn from smeared blobs to a glittering sphere of star dust.

Also, dont forget the planets, double stars and the Moon are excellent targets for your scope, I spent many nights going through double stars lists when I had a smaller scope and still find the Moon a great object, picking out the craters and trying to remember as many names as possible.
For double stars, the colour and brightness contrasts can be very interesting and taking on the challenge of splitting them is fun, seeing how far can you push the scopes resolution and magnification limits is always interesting.

So you see, there is quiet abit you can do with your scope besides the usual DSO's. and I wouldn't be too worried if you don't get spectacular views of them.

Its all about light gathering power which is dependent on scopes aperture, there are charts on the main website that allow easy comparisons of light gathering power of different sized scopes, see
http://www.shannonsideastronomyclub.com ... e_help.htm

Peter Deedigan
Posts: 3
Joined: Mon Apr 22, 2013 10:44 am

Post by Peter Deedigan » Tue May 21, 2013 10:05 am

hi Frank, Dave,

thanks for the replies, appreciate it.

regards,
peter

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