Comet 51P/ Harrington. 21 June, 2015.
Combination of 5, 3 minute images unfiltered.
SBIG STL-1001E CCD. 20" f/6.8 cassegrain at prime focus.
Comet 51P/ Harrington is generally a faint periodic comet with a period of about 7.6 years. The 2015 return was fairly favourable and the comet was expected to reach around 13th magnitude. However during July 2015 the comet was observed to disintergrate in several fragments, none of which became brighter than 16th magnitude.
The increase in brightness of the comet and of the tail in the 4-day interval between these images is very marked. This is most likely caused by the disintergration of the comet during that interval. Only 2 weeks later the comet was almost invisible!
