Eclipses/Earth axis precession
Posted: 15.02.2006, 04:06
Probably this was asked before, but I didn't find this on the forum.
What model does Celestia use for eclipse prediction? Do you include earth axis precession in all models?
I tried to check several recent eclipses, they more or less coincided with NASA bulletin date. But then, following the recommendation here, I decided to check
the total eclipse of January 14th, 484 CE in Athens. Surprisingly enough, the eclipse was first of all off by time and place, and it seems to be annular instead of total. But what is worse, the time of sunrise in Athens was somehow off by more than an hour from the correct value. May be this is because the earth axis precession is not taken into account? Or you forget to include ET-UT?[/url]
What model does Celestia use for eclipse prediction? Do you include earth axis precession in all models?
I tried to check several recent eclipses, they more or less coincided with NASA bulletin date. But then, following the recommendation here, I decided to check
the total eclipse of January 14th, 484 CE in Athens. Surprisingly enough, the eclipse was first of all off by time and place, and it seems to be annular instead of total. But what is worse, the time of sunrise in Athens was somehow off by more than an hour from the correct value. May be this is because the earth axis precession is not taken into account? Or you forget to include ET-UT?[/url]