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Re: Lewis and Clark lunars
From: Ken Muldrew
Date: 2004 Apr 23, 16:18 -0600
From: Ken Muldrew
Date: 2004 Apr 23, 16:18 -0600
On 23 Apr 2004 at 17:31, Fred Hebard wrote: > A one-day error would come close to 15 degrees. But the moon would almost be on top of Regulus, and too close to the Eastern horizon to assume a mistaken star on that side. I just checked the Regulus data and found that the error for each measurement is between 8 and 12 minutes, with an average of 10'. Since it's consistently in the same direction as the 15' error for the Aldebaran/Betelgeuse measurements, it might be close enough to be convincing evidence that L&C were reading from the wrong side of the sextant on that night. I have probably underestimated the error because I haven't taken temperature into account. Since Regulus is pretty close to the horizon here, I wonder if the cold temperature could have increased the apparent distance by enough to close the gap. > Do moon altitudes > accompany the lunar distances? These would settle this question > quickly. I don't think L&C ever took moon altitudes. The astronomical notebook that George Huxtable has transcribed and put on the web instructs them in calculated altitudes, and I believe the Preston paper also discusses their lack of lunar altitudes. It would have been nice if they did, though. Ken Muldrew.
