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
Richard Miles