IAU circular No. 9107, issued on 2010, Jan. 14, announces the discovery by G. J. Garradd of an apparently asteroidal object, on CCD images taken with the 0.5-m Uppsala Schmidt telescope in the course of the Siding Spring Survey. After posting on the Minor Planet Center's 'NEOCP' webpage, Garrad itself and other observers have noted the cometary appearance of this 19.0 magnitude object, designated C/2010 A4 (SIDING SPRING).
We have been able to confirm this object remotely, through the GRAS network, using a scope located in Mayhill (NM): on 2010, January 13.4, co-adding of 20 unfiltered exposures, 120-seconds each obtained by means of a 0.25-m, f/3.4 reflector + CCD, show a diffuse coma nearly 8" in diameter with a very weak central condensation.
Our confirming image:
Here you can see a bigger version:
The first and preliminary orbit for comet C/2010 A4 (SIDING SPRING) indicates perihelion on Oct. 8, 2010, at about 2.7 AU.
This is the 67th comet for the Siding Spring Survey.
by Ernesto Guido & Giovanni Sostero