Triple comets P/Brewington
Bill J Gray Mar 16, 2003
Hi Ben,
The reason you're seeing three comets is due to the very
odd nature of comet nomenclature. Guide's built-in database
includes P/Brewington (1992XIV), its identifier at the previous
apparition in 1992. That's the identifier given to it in Guide's
list, but comet nomenclature before 1995 was a bit of a mess:
the same comet is also known as P/1992 Q1 and 1992p.
(Even after some reforms in 1995, it's still not totally
straightened out, as you'll see.)
Guide is bright enough to realize that the elements for
1992 XIV apply to the previous apparition, not this one. So
you aren't even seeing this incarnation of the comet. (Set
Guide to a date between 1987 and 1997, and you presumably will.)
Just before P/Brewington was recovered, MPC provided elements
for a current epoch, but with the old P/1992 Q1 designation.
Once it was recovered in late 2002, it got the "new-style"
designation P/2002 Q4. Then it became a permanently-numbered comet,
154P. I suspect that at one time or another, you've downloaded
elements with each designations, and Guide isn't quite bright enough
to figure out that all three are really one and the same. To help it
along, go to "Extras... Edit Comet Data", and select P/2002 Q4 and
delete it. Then do the same for P/1992 Q1, leaving the only
"current" one: 154P.
-- Bill