[BAA Comets] [comets-ml] 29P outburst ?

Thu Jun 13 11:15:29 BST 2013

Dear Jean-Francois, Clay et al.,

Yes, indeed. A number of amateurs keep close watch on this object. I 
observed 29P on June 11.35 through cloud using the Faulkes Telescope North 
and found it to be fainter than 16.0R. Can you indicate the exact time of 
your pre-outburst observation of June 12 as it would be nice to fix a 
relatively exact time for the start of the present outburst?  Thanks.

I should mention that I have developed a model of this comet's nucleus and 
thereby a possible explanation of its behaviour. Abstracts have been 
submitted to the forthcoming European Planetary Science Congress (September 
8 - 13, London): one an oral presentation entitled, "Microporosity, the 
wetted layer and the role of CO and CO2 driving the activity of comets 
29P/Schwassmann-Wachmann and 17P/Holmes", and a second as a poster 
presentation with my colleague George Faillace, entitled, "Microporosity, 
the "wetted layer" and the postulated outburst mechanisms driving the 
activity of comets 29P/Schwassmann-Wachmann and 17P/Holmes".

I might also add that on April 19, I am on record as predicting another 
outburst of 29P on June 14 (+/-5 day). That it has outburst virtually on cue 
is one thing and may just be a chance coincidence, but what will be 
important now is to monitor the nature of the expanding outflows of material 
in the inner coma. The hypothesis I am working on for this prediction is 
that at any one time there are very few active regions on the nucleus 
involved in outbursts and that the present outburst originates from the same 
site which produced the recent (weaker) April 14 outburst: the difference in 
time of 59 days being associated with an approx. 60-day rotation period for 
the nucleus. If the form of the outflows of material seen this time for 29P 
are broadly similar to the April 14 event then the point will be finally 
proven. I say this as our data has shown this characteristic behaviour 
already occurred in 2010, 2011 and in 2012.

BTW: The way in which an outburst appears to strip away the existing 
nebulosity around the nucleus, which Clay comments on below, I have also 
noted in the past. Whether this is real or a contrast effect needs working 
on further.

Finally, observations of 29P on June 13.32 made by Maui Community College 
using the FT North (1.1" seeing) show the comet as essentially stellar in 
appearance and magnitude 13.0R.

Richard Miles
British Astronomical Association

P.S. Have just seen that Josep M. Bosch has posted a report for 29P that on 
June 12.88 the comet was magnitude 16.4R so the time of the present outburst 
must be June 12.94 +/-0.05.  Nice result.

----- Original Message ----- 
From: "P. Clay Sherrod" <drclay at tcworks.net>
To: <comets-ml at yahoogroups.com>
Sent: Thursday, June 13, 2013 3:31 AM
Subject: Re: [comets-ml] 29P outburst ?

> Yes, we confirm here at Arkansas Sky Observatories ASO/H45.
> A remarkable and surprising 24-hour outburst from magnitude 16.1 (m2) on 
> June 12 UT
> to its present magnitude 13.2 (m1) tonight.
> In addition the comet has a remarkable transition in morphology from last 
> night, with
> an outer irregular perimeter of nebulosity surrounding a stellar nucleus 
> to a very
> large and dense coma/nuclear center measuring 15" arc across with a sharp 
> perimeter
> and very little outer nebulosity (very faint to E and South of core).
>
> The comet once again shows that it deserves to be monitored regularly, 
> often and
> carefully.
>
> This is a quite substantial outburst.
>
> Dr. Clay
> _____
> Arkansas Sky Observatories
> MPC H45 - Petit Jean Mountain South
> MPC H41 - Petit Jean Mountain
> MPC H43 - Conway West
> http://www.arksky.org/
>
> ----- Original Message ----- 
> From: "Soulier Jean-FranÃ§ois" <jeffcomete at yahoo.com>
> To: <comets-ml at yahoogroups.com>
> Sent: Wednesday, June 12, 2013 8:50 PM
> Subject: [comets-ml] 29P outburst ?
>
>
> Good evening.
>
> 29P S-W1 seems to be outburst ...
> Around +3 mag. compared with measurements made by the François Kugel 
> 20130610.88 :
> http://comet.observations.free.fr/display-obs1.php?Num=9609
>
> measures :
> NET UCAC-4
> 0029P C2013 06 13.00951 13 35 42.06 -21 13 33.4 13.2 N
> 0029P C2013 06 13.02021 13 35 41.96 -21 13 32.0 13.1 N
> 0029P C2013 06 13.03167 13 35 41.87 -21 13 30.6 13.1 N
> ----- End -----
>
> 29P field :
> http://6888comete.free.fr/images/forum/29P20130613.jpg
>
> DSS :
> http://6888comete.free.fr/images/forum/DSS29P.jpg
>
> Thank you to confirm this observation ...
>
> Sincerely.
> SOULIER Jean-François
> C10/France
>
>
> [Non-text portions of this message have been removed]
>
>
>
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