[BAA Comets] Outburst predictions for Comet 29P/Schwassmann-Wachmann

[Richard Miles]

This comet appears to have at least 5 or 6 active sites on its nucleus. 
Several appear to show seasonally-dependent activity and since last 
September a new season has been developing making predictions more 
uncertain. Still it is worth sticking one's neck out at times to encourage 
observers, so here goes!

One source, referred to here as 'b', tends to exhibit relatively strong 
outbursts and happened to account for the very latest event which occurred 
on 2015 February 25.85 (+/-0.17). On average, Source 'b' will outburst about 
once every 7 or 8 months. I estimate that there is a 20-40% chance it will 
outburst on the next revolution of the nucleus, in which case this could 
happen on April 23.9 (+/-3.5 d), i.e. between April 20.4 - 27.4

Unfortunately the comet is located in a very dense part of the Milky Way 
near the border between Scorpius and Sagittarius at a declination of -31.6 
degrees, so detecting a small outburst may prove challenging. The comet is 
currently quiescent at around R magnitude of 16.5-17.0 but if it does 
outburst then this may suddenly change to 14.5-15.0 or so.

If no outburst occurs this time around, then watch out on June 20.6 (+/-3.5 
d) or August 17.4 (+/-3.5 d) since each revolutiuon that it fails to 
trigger, the more likely the event will happen on its subsequent revolution.
N.B. Other sites on the nucleus might outburst at certain other times.

Clear skies,
Richard Miles
BAA