Two questions about viewing with my Nexstar 8SE telescope..

[ILoveKnowledge]

Hi all! I have a Celestron Nexstar 8SE telescope and I even bought the GPS unit for it! For some reason with deep space objects away from the immediate planets, I have trouble accurately centering the three stars during the alignment procedure and while near space objects such as the planets work well with the "GoTo" hand controller, the deep space objects always seem to be slightly off. Do you have any tips or hints on what I should do? Also, if the objects are slightly off, what is the best way to find the objects? Use a star map? I was hoping that with my GPS skysync unit my alignments would be completely on target. It is a little frustrating. All tips and hints would be highly appreciated.

In addition, I haven't been able to take it somewhere away from the night sky of the city yet, so I understand my viewing capabilities will be severely limited until I do so (even though I have an urban city filter). Anyhow, I can of course see the planets beautifully and even star clusters; but I have not been able to yet see galaxies or nebulae. What kind of deep-sky objects can I expect to see with my 8SE both in the city and then away from the city?

Thanks in advance for your input!

[redshifter]

I can't answer the first question, and without knowing where you live, how big your city is, and how close you observe to it, it's tough to know just how much light pollution you're dealing with. Some of the brighter galaxy/nebula DSO's will show up in your scope using the filter while in a light polluted area, but using your scope in a true dark sky without the filter will be a far superior viewing experience IMO. DSO's you can see at all from the city will be much more detailed and brighter from a dark sky. Many DSO's will be nearly impossible to see or very dim until you get to a dark sky.

Think of it as the difference between standard def TV on an old black n' white TV set vs. a modern HDTV.

[RickJ]

Also keep in mind galaxies and nebula will not look at all like their pictures (one exception is the Ring Nebula however). The usual reaction of a beginner looking at the faint indistinct glow of the Andromeda galaxy is; "That's it? I only see a smudge." Yep that's it. Photos store light over a period of time. Our eye sees all it is going to see in about 1/10th of a second my eye doctor tells me. It takes a lot of practice to train the eye-brain to see such faint objects.

From town start with open star clusters such as M11. Not knowing where you are I can't be specific but M11 is a good starter cluster visible from most of either hemisphere (Far north excepted). As you learn to see more Globular star clusters like M13 and M92 will show individual stars with enough power once you've started to train the eye-brain to see faint details. Small bright planetary nebula would be next on the list. They respond well to OIII filters IF you can get your eye well dark adapted by being shadowed from city light sources. If, after dark adaption, house lights are "blinding" then you were sufficiently dark adapted. I've never found ordinary general light pollution filters to be of much use. But for objects rich in OIII light such as most bright planetary nebula and some emission nebula they can do wonders. But again, the better trained your eye-brain are the more you will see and this training takes time. Also these filters block a lot of starlight so stars will become very faint to invisible. The loss of stars to focus the eye on is a problem some beginners have. So much so we gave up on such filters at the public observatory I was at for 27 years. They were lost without the stars and couldn't see anything. Some could but far too many couldn't so we gave up the idea. General LP filters let stars through but had only a very minor effect. We use them but I can't say I see any difference in how the public reacts when used or not used. Our operators which have trained eye-brain systems do see a small gain so we continue to use them but leave it to that scope's operator to use or not use as they see fit. About half did and half didn't when I resigned as supervisor and moved up here.

In a dark setting with a well trained observer an 8" scope will show you many thousands of objects but most will be just small smudges. Much of the enjoyment comes from understanding what the smudge is! In some fields you will see many smudges. Determining which is what can be quite challenging. Which one is the Messier galaxy being sought and what NGC galaxies are the rest can be quite challenging in fact.

Rick