C/2007 N3 Lulin
more info
Comet C/2007 N3 was discovered on 11 July 2007 with Lulin Sky Survey (Taiwan); that is about 1.5 years before its perihelion passage. It was observed until 1 January 2011 (see picture).
Comet had its closest approach to the Earth on 24 February 2009 (0.411 au), about 1.5 month after its perihelion passage.
Preferred solution given here is based on data spanning over 3.48 yr in a range of heliocentric distances: 6.38 au – 1.212 au (perihelion) – 7.82 au.
This Oort spike comet suffers rather large planetary perturbations during its passage through the planetary system and these perturbations lead to more tight future orbit with semimajor axis of about 1,200 au (see future barycentric orbits).
For more details see Królikowska and Dybczyński 2013 and Królikowska 2020.

solution description
number of observations 1588
data interval 2007 07 11 – 2009 01 08
data arc selection data generally limited to pre-perihelion (PRE)
range of heliocentric distances 6.38 au – 1.21au
detectability of NG effects in the comet's motion comet with NG effects strongly manifested in positional data fitting
type of model of motion GR - gravitational orbit
data weighting YES
number of residuals 3132
RMS [arcseconds] 0.33
orbit quality class 1a
orbital elements (barycentric ecliptic J2000)
Epoch 1710 02 26
perihelion date 2009 01 09.70750001 ± 0.00003937
perihelion distance [au] 1.20595272 ± 0.00000095
eccentricity 0.99996465 ± 0.00000072
argument of perihelion [°] 136.943949 ± 0.000153
ascending node [°] 338.502617 ± 0.000145
inclination [°] 178.368253 ± 0.000005
reciprocal semi-major axis [10-6 au-1] 29.31 ± 0.59
file containing 5001 VCs swarm
2007n3pa.bmi
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.
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.