C/2014 W6 Catalina
more info
Comet C/2014 W6 was discovered on 20 November 2014 by R.A. Kowalski and W.H. Ryan during Catalina Sky Survey, that is four months before its perihelion passage, and was observed until 20 July 2015. This comet had closest approach to the Earth on 12 March 2015 (2.21 au, a week before the perihelion passage).

Despite the large perihelion distance (3.01 au), this is a comet with NG effects determinable by positional data fitting (solution 'c5'). However, this NG solution gives marginally hyperbolic original orbit with large uncertainty. Therefore, because of the similarity of the original semimajor axis obtained from GR solutions 'a5' (entire data arc) and 'p5' (pre-perihelion data arc), and the narrow range of heliocentric distances for NG orbit determination, the solution 'a5' is proposed here as the preferred orbit. Solutions 'a5' (GR, preferred) and 'c5' (NG, sublimation of more volatile icesd than water ice) are based on data spanning over 0.66 yr in a range of heliocentric distances: 3.30 au – 3.01 au (perihelion) – 3.31 au.

This Oort spike comet suffers tiny planetary perturbations while passing through the planetary system; these perturbations probably lead to a slightly more tight future orbit.
solution description
number of observations 116
data interval 2014 11 20 – 2015 03 15
data arc selection data generally limited to pre-perihelion (PRE)
range of heliocentric distances 3.3 au – 3.09au
detectability of NG effects in the comet's motion comet with determinable NG~orbit
type of model of motion GR - gravitational orbit
data weighting YES
number of residuals 223
RMS [arcseconds] 0.38
orbit quality class 2a
previous orbit statistics, both Galactic and stellar perturbations were taken into account
no. of returning VCs in the swarm 5001 *
no. of escaping VCs in the swarm 0
no. of hyperbolas among escaping VCs in the swarm 0
previous reciprocal semi-major axis [10-6 au-1] 75.99 – 84.39 – 93.09
previous perihelion distance [au] 2.43 – 2.67 – 2.86
previous aphelion distance [103 au] 21.5 – 23.7 – 26.3
time interval to previous perihelion [Myr] 1.1 – 1.3 – 1.5
percentage of VCs with qprev < 10100
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).
previous_g orbit statistics, here only the Galactic tide has been included
no. of returning VCs in the swarm 5001 *
no. of escaping VCs in the swarm 0
no. of hyperbolas among escaping VCs in the swarm 0
previous reciprocal semi-major axis [10-6 au-1] 75.99 – 84.42 – 93.13
previous perihelion distance [au] 2.66 – 2.78 – 2.87
previous aphelion distance [103 au] 21.5 – 23.7 – 26.3
time interval to previous perihelion [Myr] 1.1 – 1.3 – 1.5
percentage of VCs with qprev < 10100