C/2007 Q3 (Siding Spring) Explained

C/2007 Q3 (Siding Spring)
Discoverer:Donna Burton
Siding Spring Survey
0.5-m Schmidt (E12)[1] [2]
Discovery Date:2007 August 25
Epoch:2455014.5
(2009-Jul-02)
Orbit:Oort cloud
Semimajor:~7,500 AU (outbound) (a)
Perihelion:2.25166 AU (q)
Aphelion:~69,000 AU (inbound)
~15,000 AU (outbound)
Eccentricity:1.0002077[3]
Period:Millions of years (inbound)
~650,000 yr (outbound)
Inclination:65.6504°
Jupiter Moid:3.13 AU
Last P:October 7, 2009

C/2007 Q3 (Siding Spring), is an Oort cloud comet that was discovered by Donna Burton in 2007 at Siding Spring Observatory in New South Wales, Australia.[4] Siding Spring came within 1.2 astronomical units of Earth and 2.25 AU of the Sun on October 7, 2009.[5] The comet was visible with binoculars until January 2010.

Images of the comet taken in March 2010 by N.Howes using the Faulkes telescope, showed that the nucleus had fragmented.[6]

The comet has an observation arc of 1,327 days and was still being observed as of April 2011.[3] 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 7,500 AU, an apoapsis distance of 15,000 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 69,000 AU (1.09 light-years). 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.[7]

External links

Notes and References

  1. Web site: 2007-08-30 . IAUC 8865: P/2007 Q2; C/2007 Q3 . IAU Central Bureau for Astronomical Telegrams . 2011-04-20.
  2. Web site: 2007-08-30 . MPEC 2007-Q44 : COMET C/2007 Q3 (SIDING SPRING) . . 2011-04-20.
  3. Web site: 2011-04-13 last obs . JPL Small-Body Database Browser: C/2007 Q3 (Siding Spring) . . 2011-03-07.
  4. Evans, Kate (February 19, 2010). "'Australian' comet captured by NASA". Australian Broadcasting Corporation. Retrieved on February 19, 2010.
  5. "Visitor from Deep Space". NASA. February 17, 2010. Retrieved on February 19, 2010.
  6. Baldwin, Emily (March 17, 2010). "Is Comet Siding Spring splitting up? ". Astronomy Now. Retrieved on March 19, 2010.
  7. Web site: Feb 17, 2010 . Multimedia Gallery: comet Siding Spring streaking across the sky . WISE . 2011-04-20.