Picking the stars for drift alignment

[swag72]

For those who are following my saga of sorting out my Polar alignment, you will know that I am waiting for a clear night (signs looking good for tonight) to get my PA as accurate as possible using PHD. Without you guys I wouldn't be here right now - So a million thank you's ................ But ............. dumb question alert!! There's another on it's way!!

I have read lots of threads and info on picking the stars for the 'alignment'. I want to know in real laymans terms what stars I need to align to. Forget words like meridian and celestial equator please!!

Here's what I think so far, but please do correct me if I'm wrong.

I select a star in the South as low in the sky as possible. In my case, as I am in something of a bowl, the lowest star I can get is Sirius - Is this one OK?

Then I move to a star in the East - I don't think this one needs to be low? I hope not as I'm looking up a hill by that time!!

In very simple, idiots terms, is that about right?

[shaunster]

Sara, If you havent allready then look at this Andy's Shot Glass - Drift Alignment for Amateur astrophotography,ccd, Neutonians and Refractors, amateur astronomy allthough aimed at someone using a reticle eyepiece, it explains the terms of meridian celestial equator

[SteveP]

Swag

When people talk of the Meridian, they just mean point the scope to the South. However, the star you select shouldn't be as low as possible. Rather it needs to be close to the celestial equator. In the UK, this is about 30 degrees of elevation - a little higher in Spain. This elevation isn't too critical. So, yes Sirius would be OK as would Mirzam, Saiph, even Bellatrix at a push and plenty of others in that region.

When looking East, something at a similar elevation to your South star would be OK.

You seem to have a hang of it now!

Steve

[themos]

Anything in Orion is close enough for the "meridian" star for azimuth adjustment. Sirius is a bit too low (15 degrees south of equator) but will do at a pinch. Procyon is better.

[themos]

I think you'll need to know the declination of the star you use so jot them down somewhere beforehand.

[swag72]

Brilliant, thank you.

[martin_h]

This will be my south view at about 8.30 tonight......anywhere around the intersection of the blue and green lines will do for south

[Photosbykev]

This will be my south view at about 8.30 tonight......anywhere around the intersection of the blue and green lines will do for south

ok how did you get the celestial equator in Stellarium? I've looked for that option and never found it

[themos]

F1 brings up a list of the keyboard commands, i think.

[Photosbykev]

F1 brings up a list of the keyboard commands, i think.

thank you, got it. It's the full stop key

[kookoo_gr]

i would like to add that if you drift align using a ccd camera you shouldn't use very bright stars like Betelgeuse or Rigel because you won't be able to see the drift that star has. for visual drift align the above stars are ok.

[adamsp123]

The Andyshotglass is excellent at explaining this concept and how to do it in practical terms, once you have found a star then use PHD to help you do the rest and BTW you don't need abright star for PHD, in fact too bright and PHD struggles.

[martin_h]

The Andyshotglass is excellent at explaining this concept and how to do it in practical terms, once you have found a star then use PHD to help you do the rest and BTW you don't need abright star for PHD, in fact too bright and PHD struggles.

Yet the couple of times ive used the auto star select it always picks the brightest star!

[adamsp123]

Yet the couple of times ive used the auto star select it always picks the brightest star!

And that is why I don't use that feature:D

I even think Craig Stark recommends not using bright stars.

[swag72]

All good stuff there folks - Thank you.

[David010167]

Hi Sara, have you tried or looked at EQAlign? I had a play with it last night having followed your other thread. Alas due to a lot of dew/condenstaion I did not to use the software fully, however it looks useful and one of the features shows you which stars to pick for the align.

regards

David

[swag72]

I haven't looked at EQAlign too closely as what I had read on here, it's not as instant as PHD. As it stands at the moment, I need to see some instant results of whether I've turned the knob the right way even! I may well try it in the future.

Fingers crossed for tonight, if there's no cloud I'll be out there, then drill holes in the patio, so that the mount goes back in the same place each time!! I expect you'll hear the swearing in UK as it all goes Pete Tong! I tried last night briefly, but it was quite windy and I was watching the star move around on screen - I don't think PHD liked the wind!!

[moocher]

EQAlign is really easy to use!!! Just pick 2 stars from the database (that you can see) GOTO to the first star and centre it. Then click align. Pick the next star and off it goes to it. Centre it. Click align again. Then the software does a bit of mathematics and moves the star to where it should be. All you have to do then is recentre the star using the mount controls (ie the knobs) and bobs your uncle!!! Takes about 5 mins if you can see both stars!!!

Alan:D

EQMOD is the best investment you can make for a EQ6 pro or HEQ5 pro....