what is the correct way to use a equatorial mounted telescope?

Question

websites with great detail would be helpful

Answer 1

You set the angle of the mount to the position of true North. If you got this correctly as you moved the telescope around Polaris should remain basically stationary in your spotting scope or a wide field eye piece.

Then you find an object with known coordinate and use that to set up your RA and DEC setting circles.

Answer 2

You have to line up the polar axis so that it is parallel to the Earth's rotational axis. One way to do this is to have a method of sighting through the polar axis and checking that it is pointing at the relevant celestial pole. This is a bit easier in the Northern hemisphere because Polaris is a fairly bright star (I think it just makes it into the top 50). In the southern hemisphere you have to locate Sigma Octantis which is quite faint. You can buy small alignment scopes, like a finder that you mount into the polar axis. Mine has a star pattern from Octans (I live in the southern hemisphere) etched into the eyepiece section so I can get about 3 or 4 stars to line up where they should so I'm pointing to the south celestial pole.

You can do a rough alignment as follows: the mount usually has a reference mark which needs to be pointed towards the north if you are in the northern hemisphere and south if you are in the southern. For this you need to know where these directions are at your observing location. A compass can help, but remember that it points to the magnetic pole and can be out by around 10 degrees (in some places local magnetic effects can render it nearly useless.) Another alternative is a good map. Then you need to tilt the polar axis until it makes an angle to the horizon that is the same as your latitude. For example, I live near 38 degrees south so I point the reference mark south and then tilt the axis so it is 38 degrees above the horizontal. There is usually a coarse angle scale marked on the side of the mount to help with this. Another rider is that the mount needs to be level before all this, my mount has a little spirit bubble so I adjust the support (a tripod in my case) until the bubble is centered.

You can get closer alignment using drift alignment (just Google those two words.) I've never really tried it and I do get rather lost reading explanations of it. Descriptions of the process for the northern hemisphere need to be altered for the southern and vice versa. Basically the idea is you point the scope at a star on the meridian, where the motion should be mostly east-west and adjust one axis to null out any movement in that direction (all this assumes you have a tracking drive and that it is turned on.) Then you look at a star near the eastern horizon, where the motion is mostly straight up into the sky and null out movement again. Then you back through it again and by now the objects should be staying steadily in the middle of the field. You need an illuminated eyepiece (with cross-hairs on it) to help notice any movement, although you can defocus the image so it is a big fuzzy blob and thus note the blob getting closer to one edge of the field with time.

I'm pretty satisfied with my polar alignment scope. It can still take me a while to get it all organised (about half an hour) but it's great when you can sit there and follow a planet for a long time. I remember being really chuffed when I was observing Mars and the scope traked nicely so I could still see it through the eyepiece even though clouds had obscured it from my unaided eye. The clouds then got too thick and I went inside for about half an hour, came back when it cleared and found the planet still there in the field (the tracking was still on of course.)

After all that there is then the fun of trying to point the scope at an object you want. The scope often doesn't move how you want it to if you are used to the Dobsonian gun turret style (which I find tends to be my natural style.) It can also be hard to steer to objects near the pole (I often get twisted up trying to point at 47 Tucanae aka NGC 104.)

Answer 3

How about an actual manual that desribes the exact setup, alignment and use?
Go to the Orion Web site www.telescope.com and at the very top of the page, in the search box type "Manuals". Look through the index and go to any one of the manuals for their equatorial mounts. I would recommend you look at the manual for the "Astroview" mount. It is very representative of the typical small to medium Equatorial mount and has excellent instructions. That should get you started.
If you need further help, I would suggest Joining an Astronomy Forum that is used to deal with folks of your experience level.
One of the best I have found is NJ Night Sky.
It is by no means the biggest, but certainly one of the friendliest and most helpul Forums around. There are lots of folks there with lots of expertise at all levels and you will NOT be referred to some link. They will answer your questions in detail. The only mistake you can make in going there, is not to ask all the questions. Their attitude is : The only dumb question is the one you DIDN"T ask" !!
Catchy ain't it? ( Glad I thought of it )

Adolph

Answer 4

Basically, you need to point the polar axis as precisely as possible at the celestial pole.

The following sources seems pretty good to me. I am a visual person so I picked sources with pictures.

Answer 5

If you're me, any way that will get the telescope to point at what you want.

But if you want to track things, you must polar align the mount.

http://www.optcorp.com/product.aspx?pid=3050