Cbet 2923, issued on 2011, November 30, reports that an apparently asteroidal object reported by the Spacewatch survey and designated 2010 UH55 by the Minor Planet Center last year, has been found to show cometary activity. The new designation is P/2010 UH55 (SPACEWATCH).

H. Sato (Tokyo, Japan) first reported the appearance of a condensed coma of size 6-8 arcsec on 2010 Nov. 17.4 UT. Satos report remained unconfirmed until the past month, when he again found the object on 2011 Nov. 3.5 to show a cometary appearance. Other observers have confirmed the cometary nature of this object.

Prompted by an alert note of Dmitry Chestnov, we performed some follow-up about this object. Stacking of 5 R-filtered exposures, 40-sec each, obtained remotely, from the Haleakala-Faulkes Telescope North on 2011, November 28.6, through a 2.0-m f/10.0 Ritchey-Chretien + CCD, shows that this object is a comet: diffuse coma about 9" in diameter, and a faint, broad tail, nearly 20" long toward west-northwest. Total magnitude m1 R about 18.2.

M.P.E.C. 2011-W82 assignes the following orbital elements to comet P/2010 UH55 (SPACEWATCH): T 2011 May 10.36; e= 0.58; Peri. = 221.62; q = 2.77 AU;  Incl.= 8.67

Giovanni Sostero, Krzysztof Rochowicz, Ernesto Guido and Nick Howes