NavList:

Kermit, you asked:  "if you can retrieve your early data, which exact coordinates did you use for "Stellarium" and for which "Stellarium time" did you request your Stellarium picture ?"

Yes, I still have the Eclipse Island location ‘bookmarked’ in Stellarium and I retrieved the time from my calculation notes. Please see the two screen captures from Stellarium. The time (18:34:37) was selected as the earliest time at which the value for Eclipse Obscuration went from 0.00% to 0.01%. Selecting a time was not without some frustration; generally,  0.01% obscuration occurred at 18:34:37 but in some Stellarium sessions it would occur one second later at 18:34:38. I do not know why this happens. These inconsistencies occur in Stellarium on fairly consistent basis, and not just with respect to time but also for most of the other figures I’ve used. Note the values for azimuth and altitude on my original puzzle post versus the same figures on the screen capture from today’s Stellarium session (for exactly the same time of 18:34:37). Because of Stellarium’s fairly consistent inconsistencies, I use Frank’s data whenever possible. 

I should also say that although the inconsistency in Stellarium's figures is readily discernible the differences are rarely significant when adjusted to the level of precision realized by the traditional measurement instruments that celnavers typically use (sextants, watches, etc.).  

Kermit, I hope this directly addresses your question and please know that I greatly appreciate your attention to detail; in fact, I’m quite impressed by it!!

Cheers,

Jim.

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