We performed some follow-up measurements of this object while it was still listed in the NEO-CP. Stacking of 8 unfiltered exposures, 300-sec each, obtained remotely on 2011, April 27.5 from the Tzec Maun Observatory (near Moorook, Australia) through a 0.15-m, f/7.3 refractor + CCD, shows that this object is slightly diffused: its FWHM is nearly twice compared to that of nearby field stars of similar brightness.

Initially the object was given the minor-planet designation 2011 GK_71 on MPEC 2011-H41 based on a series of one-night astrometry (Apr. 14) from Spacewatch (that shows little or no cometary appearance). Other observations obtained with the Steward Observatory Bok 2.3-m f/3 reflector (+ 90Prime CCD camera) during Apr. 29.256- 29.301 in 1".3 seeing, shows the object appears nearly stellar, but with a coma diameter of 5" and a tail 9" long in p.a. 111 deg.

MPEC 2011-J24 assignes the following preliminary parabolic orbital elements to comet C/2011 H1: T = 2006 Jan. 31.13; Peri. = 100.93; q = 6.91 AU; Incl. = 73.98; Node = 35.58

According to COCD webpage, this is the 36th comet for the Mt. Lemmon Survey.

by Giovanni Sostero & Ernesto Guido