Your an amateur astronomer? Great!
Off subject slightly, thought you may be interested
I took this image last weekend of the Great Globular Star Cluster in the Constellation Hercules.
It's located approximately 25,000 light years from earth, and has several hundred thousand suns or stars.
I obtaind this image with a series of 12-60 second exposures, aligned and stacked in DSS.
Image taken with a Canon 40D, mounted on a LX200 10", w/6.3 focal reducer.
A new light pollution filters was installed in the imaging camera, and seems to work really well.
Very nice shot of M13! You must know your stuff.
Hard to believe how far away some of these things are. 25,000 light years works out to about 25,000 x 5.9 trillion miles (one light year = 5.9 trillion miles). If you could plant yourself within that cluster instantaneously and then look back at Earth, you would actually see the Earth as it appeared during the last ice age. That is, if there was a telescope so powerful. I know, a lot of 'ifs' there.
Here's a website I'm sure you will appreciate:
http://www.photomeeting.de/astromeeting/_index.htm
I love M13. It’s one of my favorite Messier objects.