A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: William Porter
Date: 2018 Oct 31, 16:22 -0700
Can I ask for a bit more help please? At 18:46:47 GMT on October 19, 2018, I see the GHA of Altair as 12.194 deg. Frank's lunar calculator puts it at 11 deg 57.8', confirmed by observation. So my derivation is wrong. Altair's RA is without doubt 19h50'47", 297.6958 degrees. I have GST of 1:53:38, 28.194 deg. Adding GMT gives GHA Aries 309.889 degrees less 297.6958, or 12.194 degrees GHA for Altair. Where am I wrong?