How do i find the celestial pole?

[inferno]

Can anyone help me find the south celestial pole? They say that sigma is the star to look for but it isn't that bright. Can i use my compass? If so how many degrees one way or the other is it off from south.
Thanx guys.

[dannat (Daniel)]

there is a map which shows the magnetic variation, its inthis thread http://www.iceinspace.com.au/forum/s...ad.php?t=10832

You can really only use the compass for the genera direction, after subtracting the variation newcastle lies on. check the articles section, there is a good one on finding SCP. I have the same trouble though

[richard omeara]

I point my mount and scope south with a compass.Point RA to 32 deg. Then do a 3 star alighment.Only took me 6 months to get it right and a lot trial and error .

[Ian Robinson]

I use my own finder chart to polar align see attachments .

Requires a properly aligned (with the polar axis of your gem) polar alignment scope in your gem.

[Screwdriverone (Chris)]

Hi Inferno,

Here is an article I wrote to help you find the SCP (South Celestial Pole). It involves looking at star patterns and "hopping" from bright stars to get you closer to the actual SCP near Sigma Octanis.

Have a look, it has pictures which show you and help you pinpoint things and was written by me when I was in the same boat as you.

Hope it helps

Cheers

Chris

[Iain]

If thE telescope has a GPS feature, can that GPS be used to determin the location of the SCP ?

[JimmyH155]

I use a magnetic compass and find it perfectly good enough for all but the most extreme long exposure shots.
I use a GOOD QUALITY hand held compass - not that rubbish from Aldi or toy shops. I got mine from a boating shop.
Make sure you are not near a large mass of metal - such as the shed with 25 car bodies in it
Find out your local magnetic variation - here in Brissie it is 12 degrees East Your location in Newcastle will probably be fairly similar.
Remember the nautical adage "Variation East steer least. Variation West, steer best. " ie for EAST variation, I point my compass needle to point exactly 168 degrees (180 - 12) The compass is now pointing due south.
So get the scope axis pointing here.
Then, you want to get the other axis pointing up the correct amount. This is simply the angle from horizontal equal to your latitude. Brissie latitude is 27.5 degrees south. Newcastle will be more. Get a piece of plywood and with a bit of schoolboy trigonometry, cut out a right angle triangle - say about 400 mm long - with one of the angles being 27.5 degrees. Then with the long side in line with the axis of your scope, the upper side of the plywood will be approximately level. Adjust with a builders level until it is, and the long side will be pointing up the correct amount. Line your scope axis up with this.

I know this seems a bit complicated, but I have used my piece of plywood for 14 years now and it only takes a few minutes,
I have taken 25 minute exposures and longer with this method and have not got any elliptical stars. Of course for just optical viewing, the scope will stay on target all night.
Hope this helps

[gary]

Originally Posted by Iain

If thE telescope has a GPS feature, can that GPS be used to determin the location of the SCP ?

Hi Iain,

Despite the triumph of modern engineering the Global Positioning System is,
for a stationary object, such a telescope, it can't provide you with a compass bearing
and is thus of no use in determining the location of the SCP. Many GPS units
are fitted with separate electronic compasses, but these also rely on the
Earth's magnetic field and for practical purposes only achieve pointing resolutions
similar to their purely mechanical counterparts.

Even at the very best dark sky sites in Australia, Sigma Octanis can be a challenging
object to identify naked eye. As suggested, a finder chart and a finder scope or pair of binoculars, is recommended.

Polaris, on the other hand, apart from being very bright, to the naked eye, is in
an extended field of comparatively nothing. Little wonder most bird migration takes
place in the northern hemisphere.

Best Regards

Gary