IAUC nr.9204, issued on 2011, Apr. 06, announced the discovery of a new comet (discovery magnitude 17.3) by R. H. McNaught on CCD images obtained on Apr. 05, 2011 with the 0.5-m Uppsala Schmidt telescope at Siding Spring . The new comet has been designated C/2011 G1 (MCNAUGHT).
After posting on the Minor Planet Center's 'NEOCP' webpage, this object has been found by several CCD astrometrists to show cometary appearance. We performed some follow-up measurements of this object while it was still listed in the NEO-CP, on 2011 Apr. 06.5, remotely from the Tzec Maun Observatory (near Moorook, Australia) through a 0.15-m, f/7.3 refractor + CCD.
Stacking of 40 unfiltered exposures, 60-sec each, shows that this object a coma nearly 8-arcsec in diameter with a sharp central condensation, short tail about 15-arcsec long toward PA 15.
Our confirming image (click for a bigger version):
MPEC 2011-G49 assignes the following preliminary parabolic orbital elements to comet C/2011 G1: T = 2011 Sep. 24.39; Peri. = 13.234; q = 1.81 AU; Incl. = 161.45; Node = 158.43
According to COCD webpage, this is the 59th comet discovery for LINEAR Survey.
by Giovanni Sostero & Ernesto Guido