NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Silicon Sea: Leg 72 -NEW
From: Michael Wescott
Date: 2001 May 29, 10:08 EDT
From: Michael Wescott
Date: 2001 May 29, 10:08 EDT
Sam Chan wrote: > For unknown body #1, the compass bearing was 349.7. > Using Can Dead Man Vote Twice At Election, correcting from > compass to true requires easterly variation and deviation be added to > compass. The variation was 10dW and deviation was 1dE, totaling 9dW. > With a compass bearing of 349.7 and subtracting 9d (since it is W) > results in 340.7. There is nothing near that location in the sky. > > I noticed that if I added instead of subtracting the compass corrections, > the location fits Polaris and Deneb, thus my initial question to you to > check the compass bearing. I figured that you started off with true > bearings and converted them to compass. > On 26 May 2001, at 13:43, Michael Wescott wrote: > > > > 6) What are the names of the two unknown bodies? > > > > -- --------------------------------------------- > > > > > > Unknown #1: > > > > > > 349.7 + 10 - 1 = 358.7d > > > > > > almost due north and altitude is about same as our latitude: > > > got to be Polaris > > > > Right > > > > > Unknown #2: > > > > > > 327.3 + 10 - 1 = 336.3 > > > > > > This is visually in the angle between Polaris to the north and Vega > > > to the northwest. GHA Aries is about 34d and Long is 67W so zenith > > > has SHA of about 33d. Looking at the starchart in the almanac, there > > > is only one navigational star between Vega and Polaris: Deneb > > > > Right Hmmm. Good point. I just *knew* what the first one was, so I didn't think too hard about the calculations. Two wrongs made it right :-) <PRE> -- Mike Wescott Wescott_Mike@XXX.XXX </PRE>