C/2020 H6 ATLAS
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Comet C/2020 H6 was discovered on 22 April 2020, about 1.3 yr before its perihelion passage. This comet was observed until 8 January 2024 (as in February 2025).

Comet had its closest approach to the Earth on 30 April 2021 (3.86 au); about six months before its perihelion passage.

The preferred NG solution ('bd') given here is based on data span over 3.72 yr in a range of heliocentric distances: 6.22 au – 4.70 au (perihelion) – 7.80 au. Orbits based on pre-perihelion and post-perihelion data independently are also presented.

This Oort spike comet suffers moderate planetary perturbations during its passage through the planetary system that lead to a significantly more tight future orbit (semimajor axis of about 2,000 au).
solution description
number of observations 792
data interval 2020 04 22 – 2021 08 23
data arc selection data generally limited to pre-perihelion (PRE)
range of heliocentric distances 6.22 au – 4.71au
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 1561
RMS [arcseconds] 0.32
orbit quality class 1a
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] 17.60 – 18.49 – 19.34
previous perihelion distance [au] 4300 – 5400 – 6700
previous aphelion distance [103 au] 99.1 – 103 – 107
time interval to previous perihelion [Myr] 10.7 – 11.4 – 12.2
percentage of VCs with qprev > 20100
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 3830 *
no. of escaping VCs in the swarm 1171
no. of hyperbolas among escaping VCs in the swarm 0
previous reciprocal semi-major axis [10-6 au-1] 16.19 – 16.94 – 17.68
previous perihelion distance [au] 1300 – 1600 – 1900 R
previous aphelion distance [103 au] 113 – 118 – 123
time interval to previous perihelion [Myr] 12.9 – 13.5 – 14 R
percentage of VCs with qprev > 20100