New with a telescope question

[hmshoberg]

Hello all, I'm very new, so please bear with me. I've always had an interest in astronomy, but it never really went anywhere, and now my husband came upon a somewhat neglected telescope. We, however, know absolutely nothing about telescopes! I'd love to see if it works, and was wondering if anyone knows anything about it... we weren't having a lot of luck. It's a Celestron CO 100. Thanks in advance!
Heather

[jlharstad]

Hello Heather;

That's a 4 inch reflecting telescope, a common design. You should be able to have success using to observe the moon, some planets, and other objects as well. There are some techniques you can learn and a little practice is required to get the maximum enjoyment out of the telescope. It looks like it's in good shape from the pictures, though it's possible there are some hidden problems. Why not bring it by one of our meetings some time and a club member can take a look at it? The beginners group (B-SIG) meets monthly and would be the ideal place to learn how to use your telescope and learn about observing the night sky with it, but you could bring it to almost any MAS meeting or public star party and someone would be more than happy to help. Feel free to ask more specific questions here in the forum too. Hope that's a good start...

[clayton]

You may find the March Beginners Special interest Group of interest. It's about using "Your first Telescope". See http://www.mnastro.org/event/b-sig-meet ... ce_id=2016

[SEmert]

In the meantime, an observation or two from the pictures. With Newtonian reflectors like yours, the open end of the tube (on the right) points to the sky, and the focuser and eyepiece is on the side of the tube near the open end. The finder scope is also near the open end. I see your finder scope is put in its holder backwards, pointing toward the back end of the scope. It needs to be turned arund to be useful! After turning it around, it will then need to be aligned to the main scope. You do that by getting the scope pointed at a bright object, then aligning the finder to the scope. Since the sky moves, it will be much easier to do the initial alignment during the day, pointing the scope to some fairly distant object like the top of an electric pole, then adjusting the screws in the mount to center the crosshairs of the finder on that object. With it at least coarse aligned, then it will be much easer to fine tune it to a bright star after dark.

Even properly aligned, the typical 6x30 finder (6x magnification, 30mm objective diameter) finderscope can be hard to use. Many people end up replacing it with a red dot "zero power" finder, like this one: http://www.telescope.com/Orion-EZ-Finde ... ord=finder

With a red dot finder, you first align it much the same way as with the finder scope, but to use it you keep both eyes open and center the red light dot seen in the screen on the finder on the object to view, and then see it in the scope.

This scope is also on an equatorial mount. EQ mounts are aligned to the sky so that as the sky moves, you can just move the scope to match the sky by only turning one knob. But it has to be positioned properly to start with. We're at about 45 degree north latitude, so the angle of the mount can be set to 45 degrees on the little scale on the mount. And it needs to be polar aligned, with the Right Ascension shaft basically pointing at Polaris, the North Star. Here is a good site which has a description of moving this type of mount around to point at the various parts of the sky. http://www.astronomyboy.com/eq/

I hope that helps get you started. And as the others have said, bring it to a star party or meeting or Beginners SIG meeting and anyone with more experience will be willing to help you with it more.

[clayton]

While our beginners class and star parties are awesome as they can be hands on and you have people to coach , there is a ton of stuff on YouTube. https://m.youtube.com/watch?v=Y2sIZGdL8Tc is just an example.

[FF2Rydia]

I see your finder scope is put in its holder backwards, pointing toward the back end of the scope. It needs to be turned arund to be useful!

Good catch Steve. I didn't notice that at first.

[hmshoberg]

Thank you so much for the extremely helpful responses! I'm really looking forward to coming to a meeting and will bring the old girl along! In the meantime, I'll see about making that switch and seeing what I can do!

[SEmert]

Heather, another thing we forgot to mention because it becomes "obvious" with some more experience, but isn't so obvious when you start out is which eyepiece to use. If you have several eyepieces, start out with the one with the longest focal length (expressed in millimeters). A longer focal length eyepiece magnifies less than a shorter focal length eyepiece. Magnification is determined by dividing the focal length of the scope by the focal length of the eyepiece.

Using a shorter focal length eyepiece with higher magnification gives you a view of a much smaller portion of the sky (the "field of view"). As a result, it is harder to get an object into the field of view at first. The lower magnification and wider field of view of the longer eyepiece gives you an easier starting point. One thing that is not obvious at first is that the main function of a telescope for astronomy is to gather more light than your eye can gather by itself, more so than magnifying the objects (although both are important). You can actually see a lot in your telescope with a lower magnification, and you have a better chance of finding it in the first place. Once you have an object centered in the field of view, you can always swap out the eyepiece for a shorter focal length one to get more magnification.

Also, what to look for... there are several other good threads in the BSIG forum pointing you to both online charts and free planetarium programs. Check out the Mag 6 Star Atlas on Cloudy Nights, and the Stellarium planetary program. Both links are in my long "Web Links for Beginners - and for all MAS members" BSIG forum topic. And of course, you can get a good idea of what is currently up in the sky at both the Astronomy Magazine and Sky and Telescope Magazine web sites.