[BAA Comets] Observers J-F Soulier and JJ Gonzalez capture Comet 29P/S-W1 undergoing a strong outburst

[Richard Miles]

For the very first time the onset and development of an outburst of 
enigmatic comet 29P/Schwassmann-Wachmann has been captured thanks to 
independent observations by Jean-François Soulier and Juan Jose Gonzalez 
Diaz on 2017 July 02. Details can be found on the BAA webpage:

https://www.britastro.org/node/10684

That BOTH observers were carrying out a time-series of CCD images at the 
SAME time is an amazing coincidence especially when it is realised that this 
is only the SECOND such strong outburst so far during 2017 and that such an 
event is more or less over and done within a time-window of about one hour!

29P was discovered 90 years ago and at last we have some hard data showing 
the onset of an outburst event. The beginning of the outburst is very sudden 
and, as such, it is clearly a singular event reminiscent of a cryovolcanic 
eruption at the nucleus. Analysis of the form of the rising lightcurve 
should provide some valuable insight into this possibility.

The actual event was also the third very significant outburst within less 
than 10 days and it is likely that the all three are inter-related in some 
way, e.g. the first event triggered the second, which triggered the third. 
Since the July 2nd event, a fourth outburst has also taken place just 3.5 
days later! See Figure 3 at the above URL to see an example of the 
photometric lightcurve these past 45 days.

Extremely well done Jean-François and Juanjo.

Congratulations,
Richard Miles
BAA