from Spaceobs Website
On the graph above you can see a selection of ten comets that approach the Sun closer than 0.5 a.u.
The red line shows the boundary, to the left of which, derived from J. Bortleís formula, is the safe zone, but to the right is the zone of disintegration. The yellow color shows Comet Elenin, with absolute magnitude obtained by visual observations, and the blue is from JPL-NASA data.
As we see, Bortleís formula, all-in-all,
doesnít work too badly. Although there is a bright exception - the
green triangle belongs to the unique
comet 96P/Machholtz, about which I
will speak next time.
On images from Sept. 1st in
the cometís coma there was no condensation visible, and that meant
the comet had already broken up into fairly small pieces, with a
maximum size of not more than a hundred meters.
It is possible that something will be
visible to large earth-based telescopes. The breakup of a
long-period comet fairly close to the Earth (on a Solar System
scale) is a rather rare event. During such a breakup we can see the
interior of the comet to better understand its construction and
On the other hand, amateur astronomers,
awaiting this comet which might have been visible to the unaided
eye, will now not see it, at least visually in their telescopes and
We will wait. The end of this story is