[Prev][Next][Index][Thread]

Re: (meteorobs) Re: Yorktown meteors



>
> Actually a solar longitude of 208.0 back in 1781 would have occurred at
> 23:22 UT on October 16. This would have been on the evening of October
> 16, 1781 in eastern USA.
>
> Bob Lunsford

Hi, Bob:

That's interesting.  The Astronomy Calculator at
http://www.halcyon.com/gml/astro/ (which generally seems to work pretty
well) gives a peak almost exactly 24 hours later than you got -- 23:13:31 UT
on October 17, 1781.  I wonder what the discrepancy is.

But the question remains -- is the change in the date of the Orionids' peak
(from around the 17th in 1781 to around the 21st now) due simply to
precession as Robert Gardner suggested, or due to precession plus other
factors?  For instance, are there changes in the meteoroids' orbital paths
over the centuries that would cause the proper solar longitude for the peak
to be something other than today's value of 208 degrees?  I suspect that
precession is the complete answer, but I'm not sure.

Dave

To UNSUBSCRIBE from the 'meteorobs' email list, use the Web form at:
http://www.tiacdot net/users/lewkaren/meteorobs/subscribe.html

Follow-Ups: References: