Denis,

Sekanina is not predicting fragmentation post-perihelion. He thinks that
fragmentation started on March 21 and he predicts that we won't see the
comet again once it is lost to ground-based observers in August.

His evidence, amongst other things, is the rapid rise in brightness up
to April 15 and then the following fall. I'm surprised that he doesn't
mention the low phase angle effect around this date. He also observes
that there is larger magnitude scatter after April 15 (he's using Andrew
Pearce's estimates from COBS) and that this is indicative of
fragmentation. We don't see this in our latest near-nucleus lightcurve
(attached) which looks smooth and well-behaved. It doesn't look like the
lightcurve of a fragmenting object to me.

His arguments using the tail morphology and AFrho seem rather more
convincing but I think more data is needed while the comet is still
observable from the ground.

Nick.

On 09/07/2024 15:34, buczynski8166 at btinternet.com (via baa-comet
list) wrote:
> Hi Jeremy,
> A distinct warning about the possible fragamentaion of C/2023A3 by the
> leading cometary scientist.
> I wonder could there be any similarity between this possible post
> perihelion  fragmentation and the fragamentation of Comet  C/1975V1 West
> which also happened post perihelion and produced a wonderful visual
> spectacle.
> Denis Buczynski
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