How do you view the northern sky after polar alignment?

newbies_husband · #1 31-12-2007, 11:24 AM

Hi All,

My wife has just purchased her first telescope and she has followed the instructions and done the polar alignment. After finishing the polar alignment the telescope is pointing south, but she wants to look at stars in the northern sky. Sorry if this is a dumb question, but how does she look at the northern sky without turning the telescope around and spoiling the alignment?

iceman (Mike) · #2 31-12-2007, 02:07 PM

Hi there and

to IIS! What type of telescope is it? and on what mount?

You should just be able to use the hand controller and use the movement buttons to swing it around. It just means the telescope can sometimes turn on its side (depending on what type of mount and telescope).

newbies_husband · #3 31-12-2007, 03:02 PM

Hi Iceman,

Thanks for the reply. The telescope is a SkyWatcher SW450 - 114mm Newtonian Reflector Telescope on an equatorial mount.

Mick (Michael) · #4 31-12-2007, 03:54 PM

This link may help, but substitute north for south and east for west in the explanation. Good luck with your new telescope.
http://www.astronomyboy.com/eq/index.shtml

Mick (Michael) · #5 31-12-2007, 04:02 PM

It would be good if someone on the forums could put a how to like this together for the southern hemisphere. This is always confusing for people starting out with a GEM.

OneOfOne (Trevor) · #6 01-01-2008, 10:16 AM

Once the mount is set pointing south, don't move it. To view in the north, the tube will basically have to do a backflip, as IceMan said. My suggestion would be after you turn it to the north, try to view objects in this direction before turning to another part of the sky and this will save a lot of moving. Also try to view objects in the west (before they get low) first and then in the east (then they will be higher). This will also save a bit of movement of the axes. An EQ mount is a lot more work to move around the skies compared to a dob, but once you find an object you can follow it (especially if you have a motor drive).

newbies_husband · #7 01-01-2008, 11:33 AM

Hi Mick and OneOfOne,

Thanks for the replies, they are very helpful. Mick, that link showing the animation was very good.

I will pass this along to my wife and hopefully she will be able to work it out now. I just have another dumb question though. I'm still a bit confused about polar alignment. The purpose is to align so that you can track the stars, but what happens once you "backflip" the tube after setting the polar alignment, does that mean that you aren't polar aligned anymore?

RB (Andrew) · #8 01-01-2008, 11:49 AM

Once you're polar aligned the scope will track the stars in any orientation.
It just means the tube may be in an awkward position that's all.

It does take some getting used to but after a while it becomes easier.

BTW Welcome to IIS.

tsuken · #9 01-01-2008, 09:21 PM

Welcome, newbies_husband

Being also a newbie, I'm about to read/watch, and bookmark that link

Sometime's I have great trouble "driving" my telescope - that's a large motivation to go to an amateur's night (or are they beginners' nights?) at the Linden observatory, which is close by to me. I'm hoping to at least get my Ls

Marko of Oz (Mark) · #10 01-01-2008, 09:45 PM

Quote:

Originally Posted by newbies_husband

I'm still a bit confused about polar alignment. The purpose is to align so that you can track the stars, but what happens once you "backflip" the tube after setting the polar alignment, does that mean that you aren't polar aligned anymore?

It's important to understand what polar alignment is. You are not polar aligning the telescope itself, you are polar aligning the RA axis of your equatorial mount. That is, you are aligning the RA axis of your mount with the axis of the Earth, so that the RA axis is pointing at the south celestial pole.

Once that is accomplished the telescope tube can be moved to point in any direction by loosening the RA and DEC clamps and the "RA axis" will remain pointing at the south celestial pole.

Now that your polar aligned your drive motor on the RA axis will turn the RA axis in the opposite direction of the Earths rotation keeping your target in the field of view.

What a mouthful. I hope I'm correct and clearer than mud.

cheers
Mark

tsuken · #11 01-01-2008, 10:19 PM

Aaaaahhhhhh - I see now something about the drive motors. Since on a polar aligned telescope movement in RA is all that's needed to track an object, the motors will just move in RA at the speed needed to counteract the movement of the Earth, yes?

Ok maybe that's obvious

I'll just claim "baby brain" secondary to lack of sleep.

hmmmm ... so why am I online at gone 10pm?

newbies_husband · #12 02-01-2008, 08:32 PM

Hi Everyone,

Thanks for the replies, they have been very helpful.

RB, I think the awkward position that the tube gets into was throwing us off a bit, we thought that it couldn't possibly be right.

Tsuken, the beginners' night sounds like a good idea. We are in Melbourne so hopefully my wife can find one locally. It is certainly much easier to see something done than to merely read about how it is done.

Mark, thanks for the explanation about polar alignment, that makes it heaps clearer. I was having trouble understanding exactly what it was and I think your explanation sums it up nicely.

RB (Andrew) · #13 02-01-2008, 08:56 PM

Quote:

Originally Posted by newbies_husband

RB, I think the awkward position that the tube gets into was throwing us off a bit, we thought that it couldn't possibly be right.

I don't blame you one bit, it ends up in all sorts of funny positions indeed.

ballaratdragons (Ken) · #14 02-01-2008, 09:44 PM

Hi newbies hubby.

If you would like some assistance, there is a group in Melbourne that might be worth contacting. They are the Mornington Peninsula Astronomical Association, or there is us up here in Snake Valley.

newbies_husband · #15 04-01-2008, 02:03 PM

Quote:

Originally Posted by ballaratdragons

Hi newbies hubby.

If you would like some assistance, there is a group in Melbourne that might be worth contacting. They are the Mornington Peninsula Astronomical Association, or there is us up here in Snake Valley.

Thanks for the suggestions. We are actually in Sunbury so both of those might be a bit far for us, but I'm sure there is something closer.

Hopefully my wife will get the telescope out over the weekend and have another go using some of the suggestions from these replies.

Thanks again everyone.