C/2008 J6 Hill
more info
Comet C/2008 J6 was discovered on 14 May 2008 by R. E. Hill (Catalina Sky Survey); that is more than a month after its perihelion passage. A few pre-discovery images taken about 9 months before comet discovery (on 24 August 2007) during Siding Spring Survey were next found. The comet was observed until 7 December 2008.
Comet had its closest approach to the Earth on 13 March 2008 (1.301 au), about a month before its perihelion passage.
Solutions given here are based on data spanning over 1.29 yr in a range of heliocentric distances: 3.32 au – 2.000 au (perihelion) – 3.41 au.
This Oort spike comet suffers moderate planetary perturbations during its passage through the planetary system; these perturbations lead to escape the comet from the planetary system on hyperbolic orbit (see future barycentric orbits).
See also Królikowska and Dybczyński 2013 and Królikowska 2020.

solution description
number of observations 393
data interval 2007 08 24 – 2008 12 07
data type significantly more measurements after perihelion (POST+)
data arc selection entire data set (STD)
range of heliocentric distances 3.32 au – 2.00 au (perihelion) – 3.41 au
detectability of NG effects in the comet's motion NG effects not determinable
type of model of motion GR - gravitational orbit
data weighting YES
number of residuals 765
RMS [arcseconds] 0.50
orbit quality class 1a
orbital elements (barycentric ecliptic J2000)
Epoch 1708 03 08
perihelion date 2008 04 10.92744663 ± 0.00016719
perihelion distance [au] 1.99507980 ± 0.00000264
eccentricity 0.99995829 ± 0.00000801
argument of perihelion [°] 10.882716 ± 0.000097
ascending node [°] 298.266713 ± 0.000076
inclination [°] 45.029452 ± 0.00004
recip semi-major axis [10-6 au-1] 20.90 ± 4.01
file containing 5001 VCs swarm
2008j6a5.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.