P/2011 Y2 (Boattini) was discovered by Andrea Boattini on 2011, Dec. 24.12 with the 1.5-m f/2 reflector + CCD from Mount Lemmon Sky Survey (part of the Catalina Sky Survey). He described the comet as having a very condensed 5″ coma and no sign of a tail in 3″ seeing.
It was subsequently placed on the NEO Confirmation Page, where other observatories (including me at 204, H. Sato from I89-Nerpio, R. Holmes et al. from H21-ARI and P. Bacci et al. from 104-San Marcello Pistoiese) confirmed its cometary appearance.
I observed it the night following the discovery: transparency and seeing were good, but it was not easy to confirm it as a comet. I measured a 8″ coma slightly elongated in p.a. 140 deg.
MPC also found some prediscovery observations back to Sept. 4.
Results were published in CBET 2958 (subscription required) and astrometry in MPEC 2011-Y49.
Here is the image: