C/2016 A1 PANSTARRS
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Comet C/2016 A1 was discovered on 1 January 2016 with Pan-STARRS 1 telescope (Haleakala), that is about almost 2 yr before its perihelion passage, and was next observed until 15 February 2020.

Comet had its closest approach to the Earth on 17 January 2018 (4.397 au); about 2 months after its perihelion passage.

Solutions given here are based on data spanning over 4.12 yr in a range of heliocentric distances: 7.31 au    5.328 au (perihelion) – 7.90 au.

This Oort spike comet suffers small 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 Dones 2023.

solution description
number of observations 1195
data interval 2017 11 26 – 2020 02 15
data arc selection data generally limited to post-perihelion (POS)
range of heliocentric distances 5.33 au – 7.9au
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 3212
RMS [arcseconds] 0.39
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] 130.07 – 130.74 – 131.41
next perihelion distance [au] 5.34034 – 5.34083 – 5.34135
next aphelion distance [103 au] 15.21 – 15.29 – 15.37
time interval to next perihelion [Myr] 0.6631 – 0.6682 – 0.6733
percentage of VCs with qnext < 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).
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] 130.06 – 130.73 – 131.39
next perihelion distance [au] 5.35588 – 5.35638 – 5.35689
next aphelion distance [103 au] 15.22 – 15.29 – 15.37
time interval to next perihelion [Myr] 0.6632 – 0.6683 – 0.6734
percentage of VCs with qnext < 10100