[BAA Comets] Extremely bright mag 12.2 outburst of Comet 29P

[Richard Miles]

I can report that a second outburst of 29P/Schwassmann-Wachmann has taken 
place on 2018 09 23.2 +/-0.1  which has raised its brightness from r mag 
13.2 to 12.2.

This is a follow-up outburst to that reported by J.-F. Soulier.

This new outburst occurred 2.6 +/-0.2 days after this first event and its 
current brightness makes it one of the four most intense outbursts in 8 
YEARS.

COD F65
OBS R. Miles
MEA R. Miles
COM Photometry aperture 3.0" radius
COM Sloan r filter
TEL 2.0-m f/10.0 Ritchey-Chretien + CCD
ACK MPCReport file updated 2018.09.23 10:11:59
AC2 rmiles at baa.u-net.com
NET UCAC-4
0029P         C2018 09 23.33122 22 55 30.00 +00 14 30.1          12.62R 
F65
0029P         C2018 09 23.33175 22 55 29.98 +00 14 30.1          12.55R 
F65
0029P         C2018 09 23.33228 22 55 29.94 +00 14 29.9          12.47R 
F65
0029P         C2018 09 23.33281 22 55 29.94 +00 14 30.2          12.47R 
F65
0029P         C2018 09 23.33333 22 55 29.93 +00 14 30.2          12.48R 
F65
0029P         C2018 09 23.33386 22 55 29.91 +00 14 30.1          12.44R 
F65
0029P         C2018 09 23.33439 22 55 29.90 +00 14 30.0          12.55R 
F65
0029P         C2018 09 23.33492 22 55 29.87 +00 14 30.1          12.42R 
F65
0029P         C2018 09 23.33544 22 55 29.86 +00 14 29.8          12.46R 
F65
0029P         C2018 09 23.33597 22 55 29.85 +00 14 29.7          12.39R 
F65
0029P         C2018 09 23.33650 22 55 29.83 +00 14 29.8          12.46R 
F65
0029P         C2018 09 23.33703 22 55 29.81 +00 14 29.6          12.46R 
F65
0029P         C2018 09 23.33755 22 55 29.81 +00 14 29.4          12.47R 
F65
----- end -----

Measured in a standard 5.6" radius aperture:

0029P C2018 09 23.33228 22 55 29.95 +00 14 30.3 12.26R F65

Prior to my checking latest images, I had decided to send an alert that 
further outbursts of this comet are very likely in the coming days. This 
event has exceeded even those predictions.

It is expected that one or more weaker outbursts will also occur during the 
next 10 days.

For the next couple of days the comet will be situated close (10-15 deg) to 
a nearly Full Moon.
Observers are encouraged to keep 29P under close surveillance.
Spectroscopic follow-up, especially in the near- and mid-infrared would be 
appreciated.
ALMA observations in the submillimetre range are also encouraged given that 
we have now witnessed a very rare bright double outburst.

Richard Miles
Brirish Astronomical Association