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 1836
data interval 2019 12 03 – 2024 07 31
data type perihelion within the observation arc (FULL)
data arc selection entire data set (STD)
range of heliocentric distances 9.08 au – 2.96 au (perihelion) – 6.81 au
type of model of motion NS - non-gravitational orbits for standard g(r)
data weighting YES
number of residuals 3587
RMS [arcseconds] 0.45
orbit quality class 1a+
previous orbit statistics, both Galactic and stellar perturbations were taken into account
no. of returning VCs in the swarm 4948 *
no. of escaping VCs in the swarm 53
no. of hyperbolas among escaping VCs in the swarm 0
previous reciprocal semi-major axis [10-6 au-1] 17.40 – 18.30 – 19.21 R
previous perihelion distance [au] 430 – 560 – 680 R
previous aphelion distance [103 au] 103 – 109 – 115 R
time interval to previous perihelion [Myr] 11.8 – 12.7 – 13.7 R
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 4552 *
no. of escaping VCs in the swarm 449
no. of hyperbolas among escaping VCs in the swarm 0
previous reciprocal semi-major axis [10-6 au-1] 17.19 – 18.01 – 18.95 R
previous perihelion distance [au] 61 – 92 – 130 R
previous aphelion distance [103 au] 105 – 111 – 116 R
time interval to previous perihelion [Myr] 12.4 – 13.4 – 14.4 R
percentage of VCs with qprev > 20100