[BAA Comets] C/2019 Y4

[Nick James]

David,

Yes, definitely a comet to keep under watch. Bear in mind though that 
the recently reported bright magnitudes (up to m1=12.2) are from imagers 
who have detected the very low surface brightness outer gas coma. Thomas 
Lehmann's result from Feb 17 had it at m1=12.2, coma diameter=8.6'.

Some of the more crazy predictions of magnitude at perihelion should be 
taken with a big pinch of salt. Also, remember that when it is at 
perihelion (q = 0.25 au) on May 31st its elongation will be a very poor 
12 deg. It was always going to get relatively bright at perihelion but 
that doesn't mean that it will be easy to see!

Nick.



On 18/02/2020 22:14, David Swan wrote:
> Hello all,
> 
> There is now quite a lot of excited chatter about Y4. I managed to take a few images this evening and get (UCAC4 R): m1=14.7 with 1 arcmin diameter coma; m2 = 15.5.
> 
> David Swan
> 
> 
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