C/2008 T2 Cardinal
more info
Comet C/2008 T2 was discovered on 1 October 2008 by Rob D. Cardinal (University of Calgary, Priddis); that is about 8.5 months before its perihelion passage. The comet was observed until 9 September 2009.
Comet had its closest approach to the Earth on 20 March 2009 (1.727 au), about 3 months before its perihelion passage.
Preferred solution given here is based on entire data set spanning over 0.939 yr in a range of heliocentric distances: 3.60 au – 1.202 au (perihelion) – 1.78 au; however, the radial component of this non-gravitational solution is negative.
This Oort spike comet suffers small planetary perturbations during its passage through the planetary system; these perturbations lead to more tight future orbit (see future barycentric orbits).
See also Królikowska and Dybczyński 2013 and Królikowska 2020.

solution description
number of observations 1323
data interval 2008 10 01 – 2009 09 09
data type significantly more measurements before perihelion (PRE+)
data arc selection entire data set (STD)
range of heliocentric distances 3.6 au – 1.20 au (perihelion) – 1.78 au
type of model of motion NS - non-gravitational orbits for standard g(r)
data weighting YES
number of residuals 2611
RMS [arcseconds] 0.39
orbit quality class 1b
orbital elements (barycentric ecliptic J2000)
Epoch 1710 09 09
perihelion date 2009 06 13.07194669 ± 0.00006060
perihelion distance [au] 1.20557052 ± 0.00000064
eccentricity 0.99997687 ± 0.00000137
argument of perihelion [°] 215.823383 ± 0.000039
ascending node [°] 309.716810 ± 0.000028
inclination [°] 56.285096 ± 0.000018
reciprocal semi-major axis [10-6 au-1] 19.18 ± 1.13
file containing 5001 VCs swarm
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.
Lower panel (panels): O-C diagram for this(two) solution (solutions) given in this database, where residuals in right ascension are shown using magenta dots and in declination by blue open circles.
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.