C/2011 Q2 McNaught
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Comet C/2011 Q2 was discovered on 26 August 2011 by Robert H. McNaught (Siding Spring), that is almost 5 months before its perihelion passage. It was observed until 26 April 2012.
Comet had its closest approach to the Earth on 26 January 2012 (2.271 au), a week after its perihelion passage.
Solution given here is based on data spanning over 0.665 yr in a range of heliocentric distances: 2.43 au – 1.349 au (perihelion) – 1.94 au.
This Oort spike comet suffers notable planetary perturbations during its passage through the planetary system that cause a tighter future orbit with original semimajor axis of about 1,000 au (see future barycentric orbits).
See also Królikowska 2020.

solution description
number of observations 105
data interval 2011 08 26 – 2012 04 26
data type perihelion within the observation arc (FULL)
data arc selection entire data set (STD)
range of heliocentric distances 2.43 au – 1.35 au (perihelion) – 1.94 au
detectability of NG effects in the comet's motion comet with determinable NG~orbit
type of model of motion GR - gravitational orbit
data weighting YES
number of residuals 202
RMS [arcseconds] 0.22
orbit quality class 1b
next orbit statistics, both Galactic and stellar perturbations were taken into account
no. of returning VCs in the swarm 5001 *
no. of escaping VCs in the swarm 0
no. of hyperbolas among escaping VCs in the swarm 0
next reciprocal semi-major axis [10-6 au-1] 1,122.08 – 1,140.44 – 1,158.57
next perihelion distance [au] 1.35414 – 1.35415 – 1.35416
next aphelion distance [103 au] 1.72 – 1.75 – 1.78
time interval to next perihelion [Myr] 0.0251 – 0.0256 – 0.0263
percentage of VCs with qnext < 10100
Time distribution of positional observations with corresponding heliocentric (red curve) and geocentric (green curve) distance at which they were taken. The horizontal dotted line shows the perihelion distance for a given comet whereas vertical dotted line — the moment of perihelion passage.
next orbit statistics, here only the Galactic tide has been included
no. of returning VCs in the swarm 5001 *
no. of escaping VCs in the swarm 0
no. of hyperbolas among escaping VCs in the swarm 0
next reciprocal semi-major axis [10-6 au-1] 1,122.08 – 1,140.44 – 1,158.57
next perihelion distance [au] 1.35404 – 1.35404 – 1.35405
next aphelion distance [103 au] 1.72 – 1.75 – 1.78
time interval to next perihelion [Myr] 0.0251 – 0.0256 – 0.0263
percentage of VCs with qnext < 10100