C/2003 A2 Gleason
more info
Comet C/2003 A2 was discovered on 10 January 2002 by Arianna E. Gleason using the Spacewatch II telescope at the Kitt Peak National Observatory when the comet was a year and 10 months before its perihelion passage. This comet was observed 3.2 yr during its four oppositions in a narrow range of heliocentric distances: 11.9 au – 11.43 au (perihelion) – 11.70 au. However, there is a long pause around perihelion lasting over 7 months (from 1 April to 11 November of 2002).
Comet had its closest approach to the Earth on 14 February 2004 (10.451 au).
This Oort spike comet suffers minor 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 Dybczyński 2017.

solution description
number of observations 149
data interval 2002 01 08 – 2005 03 31
data type significantly more measurements before perihelion (PRE+)
data arc selection entire data set (STD)
range of heliocentric distances 11.9 au – 11.43 au (perihelion) – 11.7 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 297
RMS [arcseconds] 0.53
orbit quality class 1a
orbital elements (barycentric ecliptic J2000)
Epoch 1687 05 17
perihelion date 2003 11 04.71256635 ± 0.01508762
perihelion distance [au] 1.42269558 ± 0.00005556
eccentricity 0.99952706 ± 0.00002901
argument of perihelion [°] 346.598477 ± 0.000555
ascending node [°] 154.566845 ± 0.000154
inclination [°] 8.065737 ± 0.000058
recip semi-major axis [10-6 au-1] 41.40 ± 2.54
file containing 5001 VCs swarm
2003a2a5.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.