C/2011 Q1 (PANSTARRS) was discovered on 2011, Aug. 20.44 by PANSTARRS team with a 1.8-m f/4 reflector + CCD from Haleakala, Hawaii, USA.
Richard Wainscoat, Marco Micheli, Henry Hsieh and Larry Denneau described it as having a FWHM of 1.2″ while stars have 1.0″.
It was subsequently placed on the NEO Confirmation Page of the Minor Planet Center under the temporary designation P1012v1 and after then, some observatories confirmed the cometary appearance, including us.
The field of view was crowded with stars and there was a vast nebulosity in the area (Veil Nebula in Cygnus) so I took over an hour of total exposure time, to be sure to have several images free of stars. The image below (old DSS field) gives you an idea of the field in which the comet was:
Stacking all the “good” images, it was quite obvious its cometary nature: FWHM was around 30% wider than stars nearby, with a 8″ compact coma and a tail several arcseconds long in PA around 340°, even if it was quite difficult to estimate due to a nebulosity in the area.
The discovery was announced on CBET 2790 (subscription required) and the astrometry, with a preliminary parabolic orbital elements, published on MPEC 2011-Q12.
This was the 4th comet discovered by PANSTARRS survey.
Below is the image: