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Guidance for operating the Celestron Astromaster

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Guidance for operating the Celestron Astromaster

Postby guillaume on Wed Feb 08, 2012 6:37 am


I have some questions relating to Celestron Astromaster 90 EQ telescope.

1) I live in the midst of a busy city in South Asia having a latitude of 10°47'2"N in the norther hemisphere and am unable to find the Polaris on any of the nights. When there is a power shutdown, even then I am unable to locate the star. Polaris being the important star for polar alignment, is awkward to locate.

2) It's awkward to locate a star or a planet through the red dot findescope. When I look into it, I can't see any star through it. If suppose, I want to see a star through it, I am unable to see the red dot. How to exactly put the object into the finderscope's view?

3) When I track any object through the Stellarium Planetarium software in my laptop, the object shows its coordinates in the equatorial system(i.e., R.A. and DEC.)Will I be able to locate the celestial object exactly by setting the R.A. and DEC. circles on the mount as displayed in the software window?

4) When I fully set the telescope and start moving it for viewing an object in the western or eastern sky(not overhead), at a certain position, the declination axis loosening knob hits with the setting circle' pointer which scuffs the knob evertime. How to overcome this and how to set the mount in a correct position, so that it's components never meet each other and create a hindrance for a smooth move of the mount on both axes?

5) I bought this telescope from you in the month of Novemeber, 2011 and took it back to my country. I didn't notice the damaged software CD in the package. But, everything was fine. Now, I am not at all able to use the cracked SkyX CD as it's not working when attempted for installation. For the sake of the damaged CD, it's not easy for me to return the entire undamaged telescope to you for an exchange. So, kindly help me with this so that I can get the software downloaded from someone or as a CD. This would be highly appreciable.

Hoping to receive your answers,
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Joined: Wed Feb 08, 2012 5:54 am

Re: Guidance for operating the Celestron Astromaster

Postby Jne_K on Wed Feb 08, 2012 8:54 am


The "busy city" tells me you have a lot of light pollution and that is going to be the villain behind most of your problems.

As for Polaris, you are going to have to use magnetic north to align the scope, then make the necessary guess above the horizon for declination. Polaris is never a bright star under the best of circumstances and yours is far from the best. Low in the sky with lots of light pollution is bad news. The good news is that, unless you are attempting astrophotography, your polar alignment does not have to be exact. You can still be off quite a bit and manage with an equatorial mount for visual purposes.

A red dot will work for you on bright objects, but it won't show you any more stars than what you can see with your naked eye and, in fact, inexpensive red dots may show you even less because of their low optical quality. Red dots are designed to be used on bright objects or help you point the scope in the right neighborhood at best. A standard optical finder scope with magnification will show you more stars, so that is an option, but unless you have experience navigating, the best solution would be to consider a computerized telescope. Awfully hard to navigate under a badly light polluted sky because you can't see a lot of stars, even for an old pro.

Yes, you can use those setting circles in exactly that way, but (there is always a but), the small setting circles on equatorial mounts at this price are rather crude, so they'll get you in the neighborhood, but you'll still need to do some hunting once you get there. Larger diameter equatorial mounts have larger diameter setting circles and that means more precision. Unfortunately, to use those setting circles, you DO have to do a good job of polar alignment, so you're right back where you started. Sorry.

You may not be able to avoid that when using the scope at other than usual elevations. Just wait till the object is more conveniently located in the sky if you can. Not that unusual on equatorial mounts.

If all you need is the CD, Celestron will likely just send you one, though you have technically voided the warranty by buying it here and taking it out of the country. If they balk, give our OP Customer Service a call and see if they can send you one. The CD really doesn't have any more info on it, though, than what you can get by going online and visiting various astronomy websites. It's just an introductory astronomy info CD. Your call as to how badly you want it.

Sorry you are having these issues, but all of us who observe under light polluted city skies with non-computerized telescopes have many of the same issues. You sometimes don't realize how nasty light pollution can be until you setup a telescope and have to deal with it.
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