Bob Terwilliger wrote: > > Dear Angelo, > > > I need to know how to calculate, with a good accuracy, the sun > > declination for April 18 1693. > > According to the Dialist's Companion, the sun's declination on 4-18-1693 was > 11.234 degrees. This was at noon on the prime meridian......
Bob, I got 11.16 as the declination for this date. See the copy of the output of Dialist. Why the difference with your answer? Is it because of your standard meridian of 75 degrees west? Then I also got 11.234 degrees, but for your noon. The Dialist's Companion Version 1.0 Latitude 51.5° N Date Sat Apr 18 1693 Longitude 0° Julian Day 2339524.00000000 Greenwich 12:00:00 pm Equation of Time + 01:00 Longitude Correction + 00:00 Total Correction + 01:00 Sun DIAL TIME 12:01:00 pm Altitude 49.661051° Azimuth 0.378911° W Declination 11.161565° Fer.
