C/2009 F4 McNaught
more info
Comet C/2009 F4 was discovered on 19 March 2009, that is 2.8 yr before perihelion passage, and next was observed 6.4 yr during seven oppositions in a range of heliocentric distances: 8.96 au – 5.455 au (perihelion) – 10.5 au.

Comet had its closest approach to the Earth on 3 June 2011 (5.179 au, almost seven months before perihelion).

NG orbits using full data-arc as well as using pre-perihelion data arc are determinable.

This Oort spike comet suffers a tiny planetary perturbations during its passage through the planetary system that lead to a more tight future orbit (see future barycentric orbit).

See also Królikowska and Dones 2023 and Królikowska and Dybczyński 2017.
solution description
number of observations 1213
data interval 2009 03 19 – 2015 08 20
data type perihelion within the observation arc (FULL)
data arc selection entire data set (STD)
range of heliocentric distances 8.96 au – 5.46 au (perihelion) – 10.5 au
type of model of motion NC - non-gravitational orbits for symmetric CO-g(r)-like function
data weighting YES
number of residuals 2353
RMS [arcseconds] 0.49
orbit quality class 1a+
orbital elements (barycentric ecliptic J2000)
Epoch 1705 07 22
perihelion date 2011 12 31.92137006 ± 0.00112854
perihelion distance [au] 5.45158290 ± 0.00000844
eccentricity 0.99976743 ± 0.00000480
argument of perihelion [°] 260.453021 ± 0.000135
ascending node [°] 53.538661 ± 0.000006
inclination [°] 79.343056 ± 0.000012
reciprocal semi-major axis [10-6 au-1] 42.66 ± 0.88
file containing 5001 VCs swarm
2009f4bc.bmi
Upper panel: 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.
Middle panel(s): O-C diagram for a given solution (sometimes in comparison to another solution available in CODE), where residuals in right ascension are shown using magenta dots and in declination by blue open circles.
Lowest panel: Relative weights for a given data set(s).
Six 2D-projections of the 6D space of original swarm including 5001 VCs. Each density map is given in logarithmic scale presented on the right in the individual panel.