On May 18, 2012 Martin Masek succeeded in the recovery of comet P/2005 K3 (McNaught) by using a remote 30cm-reflector in Argentina. Comet P/2012 K2 (McNaught) was then a 17.5 mag object, positioned in the southern parts of Aquarius (CBET 3114). Assuming a similar brightness evolution as in the year 2005 the comet should peak at 12.5 mag at perihelion in September. During the most interesting weeks it will move through the constellations Pisces, Triangulum and Andromeda, thus being well-placed for users of larger instruments. The comet was assigned the permanent designation 260P/McNaught (P=7.07a).
Despite its relative faintness 8 observations by 4 members of the German Comet Section were received. According to these and 50 international observations the brightness parameters result as m0=12.5 mag / n=2, yielding a maximum brightness of 12.2 mag at the end of September 2012.
Total Brightness and Coma Diameter
The apparent coma diameter increased from 1.3' at the start of the apparition to 2.0' at the beginning of October. Thereafter it shrunk, measuring 1.5' at the end of November. This implies an absolute coma with a constant diameter of 45.000 km throughout the apparition. During the apparition the coma grew more and more diffuse with the degree of condensation at DC 5 at the beginning and at DC 3-4 in mid-November.
Andreas Kammerer
