A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Bob Goethe
Date: 2016 Aug 1, 09:42 -0700
Well, it looks indeed like I was misled by my enthusiasm. I will try again, particularly with Sirius, to see if I can replicate any of my July 29 results. We have had a summer full of thunderstorms here in Edmonton (and yes indeed, Edmonton is home), so it could take a little while. July 29 was extraordinary for sporting a crystaline blue sky on just the day I wanted to try my hand at photographing stars.
A person who works at the local planetarium told me that she has seen Sirius in the daytime through the telescope they have on site. The question is whether my Canon G10 can pick up on that or not.
I have taken a second look at my alleged Aldebaran photo, and I find a single pixel that is of a slightly different shade from the surrounding blue sky. See attachment. The difference is so minimal that I would be inclined to treat it as digital noise...except that its location is roughly where the Stellarium reconstruction would have me look for it. I have attached the photo and circled the questionable pixel in yellow. What do you think? Noise, or star?
On a completely separate topic, we had tornado warnings for a community 20 miles west of my house last night. I was looking to the west, and wondering whether the thunderclouds that triggered the warning were visible to me or below my horizon. That will be related to the height of the clouds I am looking at, of course. But Bowditch's Table 15 was not really designed with clouds in mind. Are there any rules of thumb for how far away I can see clouds of various sorts?