C/2015 X5 PANSTARRS
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Comet C/2015 X5 was discovered on 6 December 2015 with Pan-STARRS 1 telescope (Haleakala), that is almost 2 years before its perihelion passage.

Comet had its closest approach to the Earth on 4 January 2018 (5.909 au); 4 days after its perihelion passage.

The preferred solution given here is based on data spanning over 4.19 yr in a range of heliocentric distances: 8.38 au – 6.80 au (perihelion) – 8.45 au.

This Oort spike comet suffers tiny planetary perturbations.
solution description
number of observations 171
data interval 2015 12 06 – 2018 02 08
data arc selection data generally limited to pre-perihelion (PRE)
range of heliocentric distances 8.38 au – 6.80 au (perihelion) – 6.81 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 332
RMS [arcseconds] 0.22
orbit quality class 1a+
next 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
next reciprocal semi-major axis [10-6 au-1] 36.50 – 37.23 – 37.96
next perihelion distance [au] 20.6 – 20.8 – 21.1
next aphelion distance [103 au] 52.7 – 53.7 – 54.8
time interval to next perihelion [Myr] 4.25 – 4.37 – 4.5
percentage of VCs with qnext > 20100
next 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
next reciprocal semi-major axis [10-6 au-1] 36.14 – 36.87 – 37.61
next perihelion distance [au] 13.5 – 14.4 – 15.3
next aphelion distance [103 au] 53.2 – 54.2 – 55.3
time interval to next perihelion [Myr] 4.33 – 4.46 – 4.6
percentage of VCs with 10 < qnext < 20100