When is a comet..not a comet?

Observers coordinating a NEO and comet recovery program using the twin 2metre Faulkes Telescopes today pushed the limits with a long duration run on a newly discovered object.

Known initially as P100ib4, this object was flagged up by the IAU's minor planet centre as displaying a potentially unusual orbit, but had only been observed on a single night.

CARA team members Nick Howes, Giovanni Sostero and Ernesto Guido, scheduled a 90 minute session on Faulkes North in an attempt to determine the objects' true nature.

P100Ib4_2011Jul01_F65.JPG"We were looking for any signs of a faint coma, as the object was moving in a cometary orbit, but initially was showing more point source/asteroidal properties".

Using the new Spectral CCD camera installed on Faulkes North, Howes tracked the object imaging using two filters. "We got close to 30 minutes of solid image data, which on a 2m scope enabled us to track it at an incredible magnitude 21.5".

Careful analysis of the image data using the Faulkes recommended software "Astrometrica" along with applications like Maxim DL showed that the object was probably an asteroid, as it displayed the same FWHM as nearby stars at around the same magnitude... but still, orbiting like a comet.

"This one has our heads scratching a bit" continued Nick, "and we'll probably continue to monitor it over the coming weeks".

The IAU's minor planet centre on July 1st issued an MPEC citing the CARA team using Faulkes. The object is now classified officially as 2011 MM4. "*The orbital inclination of almost 100 degrees and a semi-major axis of 16AU's makes this a highly unusual object and one which warrants closer scrutiny" says Nick Howes. "Thankfully Faulkes is here to support these and other ongoing projects"

(*Thanks to Dave Grennan for calculations on this)