Friday, August 29, 2008

New Comet C/2008 Q3 (GARRADD)

IAU Circular nr.8968, issued on 2008, August 28th, announces the discovery by Gordon Garradd of a new comet, named C/2008 Q3 (GARRADD). It was picked-up in the southern constellation of Phoenix, through the 0.5-m Uppsala Schmidt telescope, on 2008 Aug 27.6.

The discoverer reported for it the detection of a 10" coma, more prominent toward north. After its posting in the NEO-CP page, A. C. Gilmore and P. M. Kilmartin confirmed indipendently the cometary nature of this object (small coma about 6 arcsec in diameter with no tail).

We performed some follow-up of this object on 2008, Aug. 28.6, using a remotely-controlled scope, located in Australia (Grove Creek Observatory). Looking at our stacking (details on image) we suspected the presence of a tiny coma, possibly elongated towad north, north-west:

http://tinyurl.com/6aqzd5

However the S/N in the stacks was not high enough to be sure about the reality of this details, and the sky conditions, initially very good, were rapidly deteriorating. So we lost the opportunity to perform during the same night additional follow-up of this target, in order to make sure about its cometary nature. Then we decided to get back into it the next nigth, but, meanwhile, its cometary nature was already published thanks to the IAU Circular nr.8968.

Preliminary orbital elements, published on M.P.E.C. 2008-Q52 (http://tinyurl.com/6ozaso), provide for this comet an eccentricity of e=1, and an inclination of i= 140 deg, that makes it moving along a retrograde orbit. Perihelion, at q= 2.5 AU will be reached in July 2009 (maximum magnitude is expected to be about 15). This comet will mostly be a southern object.

Updated ephemerids of C/2008 Q3 are available, as always, in the website of the minor planet center:

http://tinyurl.com/59xlud

During the same oberving session, we also performed some follow-up of the new discovered Aten-type minor planet 2008 QV11 (http://tinyurl.com/57tq56), a "chunk of rock", about 200-m in diameter, that was passing about 0.2 AU from Earth.

by Giovanni Sostero, Paul Camilleri and Ernesto Guido

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