A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Jim Vrancik
Date: 2020 Oct 3, 13:29 -0700
I have a strange and maybe silly problem. I just bought a telescope with the idea of studying and photographing the moon. My house is surrounded by tall trees, and the only view that I have of the ecliptic is a 30-degree gap in the trees. Azimuth of about 150 degrees to 180 degrees. So, I wanted to develop a little program, either in excel or java or python to tell me the following: When is the moon in that gap between the hours of 1 hour past sunset to about 11:00pm? So, accuracy is not a big driver, but I do not want to be deliberately sloppy if I can avoid it. Aries is pretty easy. Good equations (via NavList Bill Murdoch 2005 Feb 11 21:10 est) or an easy empirical equation. Adjustments for the equation of time and difference in Longitude gives me a good GHA of the Sun. I still need to adjust sunset for the Latitude. But the moon has been my biggest problem. Yesterday I did find a neat excel program from Navigation Spreadsheets that may solve my moon problem, but I actually like the idea of trying a table lookup of the GHA moon then interpolating to get the accuracy. This is probably more info than you wanted, but you did ask. So, do you have any hints as to where I can download the moon table (could be in any format, excel, CSV, or any other)? And by the way, thanks a lot for the attention you have given me (this). I really appreciate it, given the fact that I am just screwing around. I have had a lot of fun just reading the NavList posts, but I do wonder what your motivation is?