C/2013 G2 McNaught
more info
Comet C/2013 G2 was discovered on 8 April 2013 by Robert H. McNaught (Siding Spring), that is about 4 months after its perihelion passage. Next, it was followed more about 4.5 months until August 25. Comet had its closest approach to the Earth on 8 June 2013 (2.05 au, 2 months after discovery).

GR solution given here is based on data spanning over 0.38 yr in the post perihelion leg of orbit in the range of heliocentric distances from 2.58 au to 3.61 au. Due to short data arc the NG orbit is not possible to obtain.

This is comet outside the Oort spike with semimajor axis of about 4050 au. Comet suffers small planetary perturbations while passing through the planetary system and these perturbations lead to slightly less tight orbit with semimajor axis of about 5350 au (see future barycentric orbits).
solution description
number of observations 111
data interval 2013 04 08 – 2013 08 25
data type observed only after perihelion (POST)
data arc selection entire data set (STD)
range of heliocentric distances 2.58 au – 3.61au
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 213
RMS [arcseconds] 0.31
orbit quality class 2a
orbital elements (heliocentric ecliptic J2000)
Epoch 2012 12 19
perihelion date 2012 12 06.34716249 ± 0.00173409
perihelion distance [au] 2.15419099 ± 0.00002957
eccentricity 1.00004329 ± 0.00001814
argument of perihelion [°] 293.913692 ± 0.001164
ascending node [°] 274.113046 ± 0.000022
inclination [°] 96.001584 ± 0.000427
reciprocal semi-major axis [10-6 au-1] -20.10 ± 8.42
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.
Middle panel(s): O-C diagram for a given solution (sometimes in comparison to another solution available in CODE), where residuals in right ascension are shown using magenta dots and in declination by blue open circles.
Lowest panel: Relative weights for a given data set(s).