C/2007 Q3 (Siding Spring)

Observations and orbit

Images of the comet taken in March 2010 by N. Howes using the Faulkes telescope, showed that the nucleus had fragmented.

The comet has an observation arc of 1,333 days and was continuously observed until September 2011. The orbit of a long-period comet is properly obtained when the osculating orbit is computed at an epoch after leaving the planetary region and is calculated with respect to the center of mass of the Solar System. Using JPL Horizons, the barycentric orbital elements for epoch 2030-Jan-01 generate a semi-major axis of 7500 AU, an apoapsis distance of 15000 AU, and a period of approximately 650,000 years.

Before entering the planetary region (epoch 1950), C/2007 Q3 had a calculated barycentric orbital period of ~6.4 million years with an apoapsis (aphelion) distance of about 69000 AU. The comet was probably in the outer Oort cloud for millions or billions of years with a loosely bound chaotic orbit until it was perturbed inward.

References

| access-date= 12 March 2025 }} Solution using the Solar System Barycenter. Ephemeris Type:Elements and Center:@0 (To be outside planetary region, inbound epoch 1950 and outbound epoch 2050)

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| archive-url= https://web.archive.org/web/20100221062114/http://www.abc.net.au/news/stories/2010/02/18/2824092.htm | url-status= dead | archive-date= February 21, 2010 | access-date= 20 February 2010 }}

| access-date= 7 March 2011 }}

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| access-date= 20 April 2011

| access-date= 20 April 2011 }}