I was just responding to another thread about aligning to the SCP, and I remembered the method I used to use with my newt 20 something years ago. I don't think I've seen too many people mention that they use it, so I offer it here in case someone can learn from it or make some use of it.
Anything to reduce frustration for newbies
. I think I learned this from an old Edmunds Scientific scope building book.
So lets assume you don't have a compass to
align your scope, and you either can't see or don't know how to (or don't want to!
) find sigma octans (or Polaris in the N hemisphere), but you can identify most of the brightest stars in the sky (a planisphere is a great help for this!
). The other thing you need for this to work well is to have the latitude / altitude set reasonably close to correctly
.
1. Pick a star you can identify that's reasonably close to the equator and the horizon (say within 30° of each), and that you know the declination for (look it up in a table of bright stars such as in the back of Astronomy 2008).
2. Set the declination of your scope to match the star (with a goto mount, if you select the star from a list it should go there). Do not adjust the dec again until finished!
3. Adjust the RA to get your scope as close as possible to the star.
4. Adjust the azimuth adjustment of the mount to get the star as close as you can to the cross hairs in your finder scope.
5. Repeat steps 3 and 4 until the star is on the cross hairs in your finder scope.
6. Repeat steps 3 and 4 until the star is in the middle of the field of view of an EP in the scope. (You can increase magnification to increase accuracy, but unless you're really confident your latitude is set correctly, there's little point).
When you've got this accurate enough for your satisfaction, you can start observing or drift aligning as appropriate.
Using this method, is usually accurate enough for visual observing. With practice, you can quickly do a rough alignment to better accuracy than you can achieve with a compass or other rough alignment methods.
I've never bothered to learn to identify sigma octans
. Recently I've tried to learn it for the sake of it, but I've never used it to
align a scope.
Al.
