Richard Miles from British Astronomical Association has been coordinating UK schools to make observations of a comet that is behaving strangely. Comet P/2010 H2 (VALES) underwent a major outburst around 2010 April 15 brightening by more than 1000 times (possibly even more than this) in a matter of a few hours. Before this date, the object was not known. After this date it had taken on the appearance of a 12th magnitude star. The comet sooon began to exhibit an expanding coma.
Observations using the Faulkes Telescope North some 15 days following the initial outburst have now revealed the presence of two extended jets of material spiraling out from the nucleus of the comet, as shown in the attached image. The locus of the most pronounced jet describes a constant rate of motion radially outwards from the nucleus equal to 0.54+/-0.03 arcsec/degree of rotation as shown in the associated plot. It is not clear whether the curvature of the jets is due to an external influence such as radiation pressure or the solar wind, or whether it is indicative of a very slow rotation rate of the nucleus. If the latter, then the rotation period of the nucleus would be exceptionally slow for this comet at around 90 days. Most comets have rotation periods of the order of 0.3-5 days. Slow rotation rates would lead to enhanced thermal stress owing to prolonged solar heating of the comet's surface and may be the underlying reason why this comet underwent a major outburst. Future observations are encouraged especially to folllow the development of the spiral structures within the coma.
Many thanks to Richard!
