Saturday 6 December 2008

2008 November notes: 2008 VV4 = 2001 XQ, 2004 XK3

With the amount of clear skies in November only amounting to about 40% of that in October, it was a rather disappointing month.

An 18th mag object discovered by the Catalina survey and observed while it was still listed on the NEO Confirmation page on Nov 7th was subsequently given the temporary ID 2008 VV4 and re-observed on Nov 12th by which time JPL was listing it as a "Virtual Impactor" with 17 possible impacts predicted, the first in 2021. While checking for other NEO targets to observe that night I noticed that 2008 VV4 was in the same area of sky and had very similar speed and direction of motion as the Amor object 2001 XQ, as listed on the Minor Planet Center's List of Bright Recovery Opportunities page at

2008 VV4 turned out to be the same as the earlier object, 17° from its predicted position and the recovery of 2001 XQ was announced in MPEC 2008-V57. With a period of 6.96 years the circumstances of this apparition were similar to when first discovered in Dec 2001, with the object being at perihelion in early December and moving swiftly south from high northern declinations during November. With the extra 7 years of orbital arc available, JPL was able to calculate that there was no danger of collision with the Earth and it was removed from their risk page at

Another object observed while on the NEO Confirmation Page and ending up being a re-discovery of a previously observed object was 2004 XK3. This time it had been picked up by LINEAR as a fast moving 15th mag object and was 14th mag when I observed it only 15 hours later. It was identified within hours by the Minor Planet Center as 2004 XK3 and removed from the NEOCP. With a period of 1.36 years it had done almost exactly three revolutions in the four years since discovery and in fact was only 7° away from the place in the sky where I had observed it four years earlier.