Of all the known objects in the Solar System, comet 29P seems to be the least well-
understood in that it is in a continuous state of activity, intermittently exhibiting
single, double or multiple outbursts quite unlike any other comet. Since 2014, a concerted
effort has been underway to try and observe this enigmatic object on a frequent basis.

Thanks to the Faulkes Telescope Project and the Las Cumbres Observatory global network of telescopes, and in conjunction with amateur astronomers around the world, the comet is monitored about 3 times a day on average. The data is collated and analysed by Richard Miles of the British Astronomical Association, whose membership is comprised largely of amateurs.

The purpose of all this close scrutiny is to try and understand the nature of its
outbursts, which are seen to occur within the space of an hour or so, after which it may be
as long as a month or two before the next such event is witnessed. We try not to miss any
outbursts and we would like to detect ever fainter events, as there seem to be many more
faint ones than bright ones. Solving the mystery of Comet 29P should provide keys to
unlocking new science to explain its bizarre behaviour.

Before and after images of the recent outburst in comet 29P

Once an outburst is detected, we have the benefit of using the 2.0-m Faulkes Telescopes in Hawaii and Australia to follow up the apparent eruption by watching in detail how the expanding cloud of dust and gas develop. A case in point happened on 2019 June 11 when the inner coma jumped in brightness by an extra 150%.

Professional astronomers, Quanzhi Ye, Michael Kelley and Dennis Bodewits operating the 1.2-m Oschin Schmidt telescope of the Zwicky Transient Facility (ZTF) on Palomar Mountain, California noticed the change on a survey image taken on June 12.45 and they posted the information on the comet user group, comets-ml. By this date, an image taken with a 1.0-m f/8.0 Ritchey-Chretien at Sutherland, South Africa on June 11.19 had already been analysed and found to be in outburst. The combined observations were published as the subject of an Astronomer’s Telegram #12871 report to alert others of the news (http://www.astronomerstelegram.org/?read=12871).

Unfortunately we were unable to capture 2.0-m follow-up images on that occasion. More outbursts are to be expected over the coming months when the comet approaches
opposition in October, brightening and moving northwards in Pisces as it does so. If a bright one occurs, we shall alert FT users of the new observing opportunity and encourage more observations especially using the larger instruments on the LCO network. Watch this space!

Richard Miles

P.S. A tutorial on observing and analysing your own images of Comet 29P can be found here: https://britastro.org/node/18562