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Re: Lewis and Clark lunars: more 1803 Almanac data
From: Fred Hebard
Date: 2004 Apr 19, 11:54 -0400
From: Fred Hebard
Date: 2004 Apr 19, 11:54 -0400
Frank, The date being off by one day also could apply to looking for the "real" star from which the measure was made. Their data seem to be adequate to within a minute in other shots, so a time error in combination with measuring to the wrong star might get a reasonable answer. Usually, in my case, I make the date blunder when 00:00 hours has already passed in Greenwich but not yet in the U.S., although usually in looking things up in the almanac. Another common blunder is to use local zone time as the entering argument into the almanac rather than Greenwich time. Now I'm not saying I make these two blunders all the time!, but they are ones for which I have to watch. Fred On Apr 19, 2004, at 12:06 AM, Frank Reed wrote: > Fred H wrote: > "Have you all looked to see whether the date is off by one day? " > > Yes, I checked into the possibility that there was some time offset > (this might arise during the transcription of observing notes, for > example). So I checked for other times during the night when the > observations might have made sense. Suffice to say, it doesn't work. > An error of whole day would be much too large if you think about it. > This error would yield lunars out of line by some 13.5 degrees. > > Frank E. Reed > [ ] Mystic, Connecticut > [X] Chicago, Illinois