C/2020 R7 ATLAS
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Comet C/2020 R7 was discovered on 15 September 2020, two years before its perihelion passage. Later a series of observations were found from 3 December 2019. This comet was observed until 31 July 2024 (as in February 2025).

Comet had its closest approach to the Earth on 15 Julyl 2022 (2.18 au); about 2 months before its perihelion passage.

Currently, the preferred NG solution given here is based on data span over 4.66 yr in a range of heliocentric distances: 9.08 au – 2.96 au (perihelion) – 6.81 au. This comet shows large trends in the O-C distribution for a purely gravitational orbit. However, still some trends in [O-C] are visible for NG solutions based on full data arc (see solution 'c5' or 'n5'), trends substantially decrease for NG orbit based on pre-perihelion data atc (solution 'pc').

This Oort spike comet suffers moderate planetary perturbations during its passage through the planetary system that lead to a more tight future orbit (semimajor axis of about 1,800 au).
solution description
number of observations 403
data interval 2019 12 03 – 2022 09 15
data arc selection data generally limited to pre-perihelion (PRE)
range of heliocentric distances 9.08 au – 2.96au
type of model of motion NS - non-gravitational orbits for standard g(r)
data weighting YES
number of residuals 802
RMS [arcseconds] 0.30
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] 19.87 – 20.74 – 21.61
previous perihelion distance [au] 754 – 836 – 903
previous aphelion distance [103 au] 91.6 – 95.6 – 99.9
time interval to previous perihelion [Myr] 9.83 – 10.5 – 11.2
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 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] 19.62 – 20.56 – 21.51
previous perihelion distance [au] 20 – 30 – 45
previous aphelion distance [103 au] 93 – 97.2 – 102
time interval to previous perihelion [Myr] 10.2 – 10.9 – 11.7
percentage of VCs with 10 < qprev < 2011
percentage of VCs with qprev > 2089