C/2007 JA21 LINEAR
more info
2007 JA21 was discovered on 11 May 2007 by the LINEAR as an apparently asteroidal object, and announced on MPEC2007-J52 (2007 May 12). Later, its cometary apperance was reported by several observers [IAUC 8837, 2007 May 13].
This comet made its closest approach to the Earth on 26 May 2007 (5.211 au), six months after perihelion passage and two weeks after its discovery(see figure).
Solution given here is based on data spanning over 1.3 yr in a range of heliocentric distances from 5.53 au to 7.14 au.
This Oort spike comet suffers very small planetary perturbations during its passage through the planetary system; however, they could lead to escape of the comet from the solar system on hiperbolic orbit (see future barycentric orbit).
See also Królikowska 2014 and Królikowska and Dybczyński 2017.

solution description
number of observations 174
data interval 2007 05 11 – 2008 08 27
data type observed only after perihelion (POST)
data arc selection entire data set (STD)
range of heliocentric distances 5.53 au – 7.14au
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 342
RMS [arcseconds] 0.47
orbit quality class 1a
orbital elements (heliocentric ecliptic J2000)
Epoch 2006 11 01
perihelion date 2006 11 14.37339800 ± 0.00315000
perihelion distance [au] 5.36815179 ± 0.00001740
eccentricity 1.00230714 ± 0.00001092
argument of perihelion [°] 93.697721 ± 0.000388
ascending node [°] 65.522369 ± 0.000030
inclination [°] 89.840317 ± 0.000022
recip semi-major axis [10-6 au-1] -429.78 ± 2.03
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