bwalter
5/9/2019 4:43 PM
Brad Walter
bswalter@hughes.net
www.mcmahanobservatory.com
Ladies and Gents,
I added a document folder in Documents named visual observing and in a subfolder of that called Using Eyes in Astronomy is a very informative presentation from the 2019 Texas Star Party on getting the most out of your eyes (and mind) for visual observing. There is also a complicated chart and instructions for its use that can help you determine visibility ofextended (not point source) deep sky object based on surface brightness of the sky, the object and (this was something new to me) the angular size as seen by the eye of the object or feature you are trying to observe. Note angular size to your eye for small angles is the angular size on the sky x magnification.Some that has an angular size of 10 arcsec on the sky has an angular of 1 degree to the eye at 360x.
Johnny Scarborough
5/10/2019 8:36 PM
Thanks for the info. The study begins!