Comet C/2011 A3 (Gibbs) was discovered on 2011, Jan. 15.51 by Alex Gibbs (during the course of the Catalina Sky Survey) in four 22-sec exposures taken with the 0.68-m Schmidt on Mt.Bigelow.
He described that the comet showed a 5″ tail in PA 270°, and its FWHM was 6.4″ larger than stars nearby.
Its cometary nature was confirmed by other CCD astrometrists, including us.
The discovery was announced on Jan. 17 on IAUC 9193 (subscription required), and the astrometry appeared on MPEC 2011-B07, together with a very preliminary parabolic orbital elements (perihelion around 2011, Oct. 4).
The image below was taken on 2011, Jan. 16.22, in the last part of the night, after some passing high clouds and after the Moonset. Seeing and transparency were good.
From my image, the coma was 10″ in diameter with a faint tail 20″ long in PA around 280°. FWHM was 35% larger than stars of similar brightness.