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Comet 29P:- Will it or won't it outburst within the next 7 days ?
The next 7 days should prove interesting on 29P.
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Here's the current apparition lightcurve.
Note that since November 24 the nucleus has continued to fade.
If it continues fading for >7 days more, the period since the last outburst will become the longest in almost 5 years of high-cadence monitoring.
The last time it was dormant for more than the current 22.1 days was 21 months ago.
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Another way to look at the stats is to say there is a high probability it will actually outburst sometime in the next week.
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In November, 29P underwent two sets of strong multi-outbursts since when the nucleus remained quiet. One hypothesis is that a significant fraction of the surface is covered by a crust that is able to withstand pressure from below exerted by cryomagma. The recent multi-outbursts might be indicative of many regions on the current visible hemisphere having lost subsurface pressure as we have seen 9 strong outbursts, the majority of which have been triggered by a preceding outburst. You could say it was a form of 'carpet bombing' by falling ejecta. This may mean that we are now waiting for the nucleus to turn sufficiently that a new site appears over the terminator where the subsurface pressure persists and a further eruption is possible provoked by the heat of the Sun.
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Keep observing and we shall see !
Richard
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Re: Doug Durig's coverage of the initial phase of 29P's recent multi-outburst
Richard, thanks for the detailed answer. Eric
On Thursday, 12 December 2024 at 12:09:08 GMT, Richard Miles via groups.io <rmiles.btee@...> wrote:
Thanks Eric,
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Re. your questions:
1. Do the graphs of weak and strong outbursts groups have similar plots within their groups and when the groups as a whole are compared with each other? YES
2. Do we have any other plots of weak followed so closely time by a strong outburst? NO PLOTS but some indications can be found
3. Do we have examples of strong outbursts followed closely in time by weak outbursts? This is something that seems quite rarely happens.
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Doug isn't on the group (as yet).
The gap between one 30-sec exposure ending and the next starting is close to 1 second.
Image scale is 0.96" per pixel (binned 4x4)
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I thought I'd post a copy of the log of successes catching outbursts from the very start.
We've been very lucky in the last couple of years.
We have plenty of data, as you can see from the list below.
I also need to analyse the times to reach half maximum light and add them to the log.
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BTW: The rise phase can be modelled in three stages.
(a) coma is optically opaque;
(b) coma is optically thinning;
and (c) coma is optically transparent with a fraction of the dust grains exhibiting slow fragmentation.
(The modelling indicates the outflow from each eruption only lasts a few minutes before it shuts down)
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Richard
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Re: Doug Durig's coverage of the initial phase of 29P's recent multi-outburst
Thanks Eric,
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Re. your questions:
1. Do the graphs of weak and strong outbursts groups have similar plots within their groups and when the groups as a whole are compared with each other? YES
2. Do we have any other plots of weak followed so closely time by a strong outburst? NO PLOTS but some indications can be found
3. Do we have examples of strong outbursts followed closely in time by weak outbursts? This is something that seems quite rarely happens.
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Doug isn't on the group (as yet).
The gap between one 30-sec exposure ending and the next starting is close to 1 second.
Image scale is 0.96" per pixel (binned 4x4)
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I thought I'd post a copy of the log of successes catching outbursts from the very start.
We've been very lucky in the last couple of years.
We have plenty of data, as you can see from the list below.
I also need to analyse the times to reach half maximum light and add them to the log.
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BTW: The rise phase can be modelled in three stages.
(a) coma is optically opaque;
(b) coma is optically thinning;
and (c) coma is optically transparent with a fraction of the dust grains exhibiting slow fragmentation.
(The modelling indicates the outflow from each eruption only lasts a few minutes before it shuts down)
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Richard
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Re: Doug Durig's coverage of the initial phase of 29P's recent multi-outburst
Richard, nice piece of work from Doug. 1. Do the graphs of weak and strong outbursts groups have similar plots within their groups and when the groups as a whole are compared with each other? 2. Do we have any other plots of weak followed so closely time by a strong outburst? 3. Do we have examples of strong outbursts followed closely in time by weak outbursts? A question for Doug, what is the time interval between successive exposures?? Eric? (K01)
On Thursday, 12 December 2024 at 11:10:56 GMT, Richard Miles via groups.io <rmiles.btee@...> wrote:
The following is an extract from the MISSION 29P website:
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Richard Miles
BAA
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Paper published documenting the first successful-observed stellar occultation by the nucleus of 29P
The paper by Chrystian Luciano Pereira et al. has just been published in the Philosophical Transaction of the Royal Society reporting .
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A new orbit for 29P had shortly before been derived by Shantanu Naidu of JPL making an accurate prediction possible. The orbit was based on 623 precise astrometric positions measured on 2.0-m telescope images obtained as part of the BAA's MISSION 29P and Faulkes Telescope Project and which were supplied to JPL in October 2022. It turned out that the MPC orbit based on >40,000 positions was very inaccurate. The occultation result indicated a bias in the MPC-derived position projected on the sky amounting to >1,300 km making previous predictions largely doomed to failure.
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The current orbital still uses the same astrometric data together with the occultation result reported in this paper. It is time we updated the 2.0-m astrometry ahead of a predicted occultation visible from Europe on 2025 Feb 05. Since Pereira et al.'s success, there have been four further stellar occultations by 29P reported.
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The MISSION 29P webpages have been updated - here's the latest lightcurve:
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In addition the COMET CHASERS team has obtained deep images (2.5 arcmin square) showing the developing complex outburst coma created by multiple outbursts, which began on November 21. You can also see an outer halo about 2 armin across that originates from the previous series that started on November 02.?
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Clear skies,
Richard
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An unprecedented two sets of 4 strong outbursts exhibited by 29P this month
We know 29P is a bizarre object but this month it has been exhibiting something we had never witnessed before. One reason may be the excellent coverage from observers in that this type of complex behaviour has been missed in the past. It is too early to review its current behaviour now as more activity may show itself in the next days and we have yet to fully analyse image data. Here is what I've just posted on the :
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2024 November 24 ¨C Quadruple outburst during the last 2.1 days with start of outbursts observed by Doug Durig from V21
The last 3 days have been dramatic! ?
These are the dates and intensity of events taking place:
2024 Nov 21.457 ¡À 0.001 ?(Intensity = 6 n.e.)
2024 Nov 21.531 ¡À 0.001 ?(Intensity = 77 n.e.) 2024 Nov 22.42 ¡À 0.08 ?(Intensity = 13 n.e.) 2024 Nov 23.52 ¡À 0.17 ?(Intensity = 51 n.e.) ?
Thanks to an observing run between Nov 21.43 and Nov 21.54 conducted by D.T. Durig, we have detailed photometry of the start phase of this complex outburst. Also COMET CHASERS have used the Las Cumbres Observatory network to follow developments as has Pepe Manteca using iTelescope in Chile. We saw another set of 4 strong outbursts on 2024 Nov 02-03. But what is really surprising is that this latest set has occurred at virtually an identical rotational phase as was previously recorded during 2021 Sep 25-27 given a 57.68-day synodic rotation period for the nucleus (rotational phase 0.72 to 0.77). It is difficult to predict what may happen next ¡
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Please keep 29P under close watch. Thanks.
Richard
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New intense outburst of 29P today (November 21)
We have witnessed another intense eruption, this one today (November 21.45 ¡À 0.12), which was first detected thanks to a?COMET CHASERS?image scheduled by Maria Eleftheriou.
Pepe Manteca had taken an image from Chile using the iTelescope T72 instrument that showed the object entirely quiescent about 8 hours earlier.
We have obtained multifilter images within about 6 hours of the eruption (intensity = 79 nucleus-equivalents).
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A lot more information is available on the and the .
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This event came about a day after Errol Simpson of COMET CHASERS obtained deep 2.0-m images of the pseudonucleus showing the previous mini-outburst coma.
Images reproduced below - Note the asymmetric outburst coma close to the nucleus directed towards roughly p.a. 45¡ã
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Here's what 29P looked like a few hours ago (image 6.2 arcmin across) after its latest intense eruption - essentially stellar in appearance, magnitude 13.2R
0029P ? ? ? ? C2024 11 21.72727 10 10 29.52 +09 34 10.8 ? ? ? ? ?13.19R ? ? ?Q62
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What will this new intense outburst coma look like in a few days?
Richard Miles
BAA
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Message to all 29P observers re. when to use a filter
Photometry is a key part of MISSION 29P and its accuracy is dependent on filters.
If you use a telescope of aperture of 0.25-m or less then you are probably best to use no filter or a luminance filter to improve SNR (precision).
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Our preferred filters are SDSS-r or Cousins-R, sometimes referred to as an Rc filter or R photometric filter.
But if you are using a larger aperture telescope then rather than use no filter or a Luminance filter, and you do not have either of the preferred filters, then please use an ordinary 'Red' filter as used in RGB colour imaging if this is available. You may have to increase the exposure time or stack a few images to increase the SNR to compensate for any shortage of photons.
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Thanks in advance,
Richard
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P.S. Message to Tim Haymes: I have uploaded your observations to the webpage. They are in line with other observations so you've made a good start to the new observing season - Thanks |
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Update on the recent multi-eruption outburst of 29P
Thank you all the observers who have monitored the outcome of this latest outburst.
After 11 days, we have seen a continual decline in intensity of the pseudonucleus as the coma expands.
There is no evidence of a mini-outburst visible but now that the brightness is approaching 16th magnitude, we should be able to detect any low-level activity in the coming weeks.
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The only other outburst of this kind we have witnessed was that during late-September 2021, which amounted to a total intensity of about 406 nucleus-equivalents.
That one appeared to have released most of the pressure beneath the crust such that only 1 further strong outburst occurred 25 days later and the remaining 200 days of continual monitoring then saw only mini-outbursts every 10-20 days.
Strong outbursts returned in August 2022 after an overall gap of some 324 days!
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Will we see something of a repeat of that untypical behaviour?
Watch this space and we shall see.
Richard
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Getting back up to speed.
I imaged the comet on Nov 12.08? at altitude 19 degrees.? The first opportunity for me in some while.? I get Mag 15.1.? Hoping the measure is not too far "off" and not effected by 31 Leo.? There is some flair in the old SCT from bright stars.
Dark and flat corrected. 10x30s stacks. (Moon setting).
C11 F5.8, 7px radius, QHY174mGPS, unfiltered 10x30s subs.? [ SharpcapPro, DSS, Astrometrica ]
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0029P ? ? ? ?KC2024 11 12.07794 10 07 56.09 +09 56 58.1 ? ? ? ? ?15.06R ? ? ?Y98
0029P ? ? ? ?KC2024 11 12.08141 10 07 56.13 +09 56 58.6 ? ? ? ? ?15.07R ? ? ?Y98 ?
2460626.57794 ? 15.087 R ?C ? 68.18 ? 27.524 ? ?UCAC4 ? 0029P
2460626.58141 ? 15.069 R ?C ? 92.80 ? 27.588 ? ?UCAC4 ? 0029P ?
Tim Haymes
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Re: 2.0-m image of 29P six days post-outburst
A short email to say I am away at present and unable to update the MISSION 29P website before November 16.
Dpo keep onserving.
One objective over the coming days is to look for and detect any follow-up outbursts from 29P¡¯s nucleus.
Good luck with imaging over the next few nights.
Richard Miles
BAA |
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Strongest multi-eruption outburst of 29P, the most intense since 2021
Thanks to all the keen observers, we have obtained very good coverage of an almost unique multi-eruption event.?
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We appear to have had 4 strong outbursts within less than 48 hours, amounting to a total of 289 nucleus-equivalents in all, i.e. the ejection of material reflecting 289x the light reflected by the nucleus alone! The nature of this event is unusually very similar to a multi-eruption event that took place over 2.4 days during 2021 September 25?27, the intensity of which totalled about 406 nucleus-equivalents. Such strong events result in a relatively spherical isotropic expansion of the outburst coma.
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In the past, when observing cadence was a lot less than we achieve nowadays, this type of event would be thought to have been a single outburst that persisted for almost 48 hours rather than a sudden release of material in several singular events. It is this type of detailed insight that shows how bizarrely this object behaves.
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Note that the were obtained when the nucleus was especially quiescent. They showed an asymmetric release of CO gas from its northern hemisphere, the coma of which I suggest looks to have been of an unusually low dust-to-gas ratio indicative of excessive leakage of CO gas without significant entrainment of dust. This finding is consistent with a strong crust that is able to retain a significant sub-surface pressure. About 30 hours later, on 2023 Feb 21.5, MISSION 29P observations showed a different region of the nucleus erupted releasing some 18 nucleus-equivalents of debris in the process. That JWST saw little CO gas escaping from that side of the nucleus indicates how effective the crust can be in trapping gas under considerable pressure - the very conditions needed to create liquid cryomagma within the nucleus. Am currently studying the JWST data, so I shall have more to say on some new findings in future notes to our 29P-ml group.?
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Richard Miles
BAA
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Re: 2024 November 2-3: A double or triple strong outburst, most intense for 2 years
Hi Tim/Wayne.
toggle quoted message
Show quoted text
I have been using the Alnitak telescope for 29p monitoring during the last apparition and reporting astrometry to MPC and photometry to Richard Miles for Mission 29, but reservations this apparition cannot commence until the comet has risen in altitude a litle more. All reservations I have requested have reported roof closed. I will be reserving daily 29p observations with this telescope in the coming days. Best wishes Denis ------ Original Message ------
From: hawley.wayne@... To: [email protected] Sent: Tuesday, November 5th 2024, 12:55 Subject: Re: [29P-ml] 2024 November 2-3: A double or triple strong outburst, most intense for 2 years Tim, Looking at the telescope reservations for the next three nights I cannot see 29P in the list, I know it was being used a while ago. Regards, Wayne On Tue, 5 Nov 2024 at 12:45, Tim Haymes via groups.io <tvh.observatory@...> wrote: Congratulations on capturing the outburst.? Very exciting !? ? ? I have had 12 days of cloudy conditions with no sign of a break. There is a high pressure area over us - my barometer has hardly moved.? ?I have refurnished some USB cables and hubs that were causing lost connections and continue to test while cloudy. ? May i ask:? What is the mpc code for the Spanish remote instrument mentioned in the October Trustees Report? ? Is it being used for 29P ? ? Clear skies!! TimY98 - Oxfordshire, UK |
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Re: 2024 November 2-3: A double or triple strong outburst, most intense for 2 years
Congratulations on capturing the outburst.? Very exciting !? ?
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I have had 12 days of cloudy conditions with no sign of a break. There is a high pressure area over us - my barometer has hardly moved.? ?I have refurnished some USB cables and hubs that were causing lost connections and continue to test while cloudy.
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May i ask:? What is the mpc code for the Spanish remote instrument mentioned in the October Trustees Report?
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Is it being used for 29P ?
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Clear skies!!
Tim Y98 - Oxfordshire, UK |
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2024 November 2-3: A double or triple strong outburst, most intense for 2 years
Here is the R photometry from the latest events: the most intense since 2022 November:
Thanks to the observers including Comet Chasers
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0029P ? ? ? ? C2024 11 01.49140 10 04 12.05 +10 26 26.1 ? ? ? ? ?17.09R ? ? ?U94 5.74" (6.15") Lum 180s T11 Manteca
0029P ? ? ? ? C2024 11 01.49375 10 04 12.13 +10 26 26.0 ? ? ? ? ?17.07R ? ? ?U94 Strong outburst at 2024 11 02.075 ¡À 0.005 17.05R => 13.40R ?(Intensity = 74 nucleus-equivalents)
0029P ? ? ? ?KC2024 11 02.10528 10 04 26.53 +10 24 36.8 ? ? ? ? ?14.38R ? ? ?L27 5.96" (6.70") Clear Soulier
0029P ? ? ? ?KC2024 11 02.12784 10 04 27.04 +10 24 32.9 ? ? ? ? ?13.92R ? ? ?L27 0029P ? ? ? ?KC2024 11 02.15349 10 04 27.64 +10 24 28.2 ? ? ? ? ?13.78R ? ? ?L27 0029P ? ? ? ?KC2024 11 02.17606 10 04 28.17 +10 24 24.1 ? ? ? ? ?13.74R ? ? ?L27 0029P ? ? ? ?KC2024 11 02.20170 10 04 28.75 +10 24 19.6 ? ? ? ? ?13.65R ? ? ?L27 0029P ? ? ? ?KC2024 11 02.21674 10 04 29.10 +10 24 17.1 ? ? ? ? ?13.62R ? ? ?L27 0029P ? ? ? ? C2024 11 02.35295 10 04 32.34 +10 23 54.3 ? ? ? ? ?13.42R ? ? ?X07 5.39" (5.57") 60s Rc T72 Miles
0029P ? ? ? ? C2024 11 02.35410 10 04 32.36 +10 23 54.2 ? ? ? ? ?13.40R ? ? ?X07 0029P ? ? ? ? C2024 11 02.35512 10 04 32.36 +10 23 54.0 ? ? ? ? ?13.40R ? ? ?X07 Strong outburst at 2024 11 02.73 ¡À 0.30 13.40R => 12.42R ?(Intensity = 112 nucleus-equivalents)
0029P ? ? ? ?KC2024 11 03.09784 10 04 49.55 +10 21 41.1 ? ? ? ? ?12.55R ? ? ?I81 5.20" (5.72") r 3x60s sky ZP unstable Buczynski
0029P ? ? ? ?KC2024 11 03.10002 10 04 49.62 +10 21 40.2 ? ? ? ? ?12.50R ? ? ?I81 0029P ? ? ? ?KC2024 11 03.10219 10 04 49.63 +10 21 40.8 ? ? ? ? ?12.60R ? ? ?I81 0029P ? ? ? ?KC2024 11 03.10436 10 04 49.71 +10 21 39.9 ? ? ? ? ?12.59R ? ? ?I81 0029P ? ? ? ?KC2024 11 03.10659 10 04 49.75 +10 21 39.6 ? ? ? ? ?12.46R ? ? ?I81 0029P ? ? ? ?KC2024 11 03.10876 10 04 49.80 +10 21 39.4 ? ? ? ? ?12.57R ? ? ?I81 0029P ? ? ? ?KC2024 11 03.11093 10 04 49.85 +10 21 39.0 ? ? ? ? ?12.64R ? ? ?I81 0029P ? ? ? ? C2024 11 03.10714 10 04 49.75 +10 21 40.1 ? ? ? ? ?12.52R ? ? ?L27 5.96" (6.70") Clear Soulier
0029P ? ? ? ? C2024 11 03.12931 10 04 50.27 +10 21 36.1 ? ? ? ? ?12.56R ? ? ?L27 0029P ? ? ? ? C2024 11 03.15504 10 04 50.85 +10 21 31.6 ? ? ? ? ?12.52R ? ? ?L27 0029P ? ? ? ?KC2024 11 03.16014 10 04 50.91 +10 21 30.2 ? ? ? ? ?12.6 V ? ? ?A77 5.81" (6.22") Clear Kugel
0029P ? ? ? ?KC2024 11 03.16550 10 04 51.10 +10 21 29.5 ? ? ? ? ?12.5 V ? ? ?A77 0029P ? ? ? ?KC2024 11 03.17013 10 04 51.20 +10 21 28.6 ? ? ? ? ?12.6 V ? ? ?A77 0029P ? ? ? ? C2024 11 03.17760 10 04 51.37 +10 21 27.7 ? ? ? ? ?12.47R ? ? ?L27 5.96" (6.70") Clear Soulier
0029P ? ? ? ? C2024 11 03.20377 10 04 51.95 +10 21 23.0 ? ? ? ? ?12.44R ? ? ?L27 0029P ? ? ? ? C2024 11 03.21883 10 04 52.30 +10 21 20.5 ? ? ? ? ?12.45R ? ? ?L27 0029P ? ? ? ? C2024 11 03.23602 10 04 52.73 +10 21 17.6 ? ? ? ? ?12.42R ? ? ?Z17 5.18" (5.55") r 180s Miles
0029P ? ? ? ? C2024 11 03.49307 10 04 58.61 +10 20 32.0 ? ? ? ? ?12.39R ? ? ?U69 5.67" (5.98") Lum 120s T24 Manteca
Strong outburst at 2024 11 03.52 ¡À 0.02 12.42R => 12.22R ?(Intensity = 38 nucleus-equivalents) may be a gradual increase
0029P ? ? ? ? C2024 11 03.56216 10 05 00.19 +10 20 20.8 ? ? ? ? ?12.23R ? ? ?F65 5.61" (5.72") r 60s Usher Comet Chasers
0029P ? ? ? ? C2024 11 03.56338 10 05 00.22 +10 20 20.5 ? ? ? ? ?12.23R ? ? ?F65 0029P ? ? ? ? C2024 11 03.56216 10 05 00.19 +10 20 20.8 ? ? ? ? ?12.21R ? ? ?F65 8.01" (8.14")? ----- end -----
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We have seen strong outbursts trigger secondary strong outbursts in this way before.
One hypothesis is that slow moving (<25 m/s) large clumps of material fall back onto the nucleus breaking the crust and initiating a new eruption. ?
More observations may show further brightening.
Clear skies,
Richard
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Richard Miles
Tim Haymes
Denis Buczynski