Any astronomers around?

[CosmicTruth]

(06-05-2014 01:09 PM)HP67 Wrote:  I'm not interested in astronomy generally, I just need a few formulas.

If anybody can help figuring x degrees after sunset or point me to a section of the book, etc. that would be great. Thank you.

Update: apparently changing the zenith value to reflect the degrees before or after the event works. There must be a way to calculate this after the fact, I'll look into that.

Back in the old days (before GPS) we used to accurately set our 41C clock, scale our LAT/LONG from a USGS topo map, then we would use a solar filter to measure the angle from our backsight point to the sun direct and reverse. The calculator would be used as a stopwatch and take the horizontal angle and the exact time and the LAT / LONG and calculate the azimuth of our backsight line.

an old ephemeris is here: http://www.rollanet.org/~eksi/2008EPHEM.pdf

the ephemeris has HP programs! I know I may be over thinking your problem but also thought readers here might be interested in this.