C/2021 D2 ZTF
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Comet C/2021 D2 was discovered on 19 February 2021 by Palomar Mountain--ZTF, that is almost a year before its perihelion passage.

Comet had its closest approach to the Earth on 7 February 2022 (2.54 au), about four days after its perihelion passage.

The preferred NG solution given here is based on data span over 2.17 yr in a range of heliocentric distances: 4.46 au – 2.95 au (perihelion) – 5.10 au.

This Oort spike comet suffers small planetary perturbations during its passage through the planetary system that lead to escape the comet from the planetary zone on a hyperbolic orbit (see future barycentric orbits).
solution description
number of observations 669
data interval 2021 02 19 – 2023 04 22
data type perihelion within the observation arc (FULL)
data arc selection entire data set (STD)
range of heliocentric distances 4.46 au – 2.95 au (perihelion) – 5.1 au
type of model of motion NC - non-gravitational orbits for symmetric CO-g(r)-like function
data weighting YES
number of residuals 1309
RMS [arcseconds] 0.48
orbit quality class 1a+
previous orbit statistics, both Galactic and stellar perturbations were taken into account
no. of returning VCs in the swarm 0
no. of escaping VCs in the swarm 5001 *
no. of hyperbolas among escaping VCs in the swarm 0
previous reciprocal semi-major axis [10-6 au-1] 8.15 – 9.98 – 11.71
previous perihelion distance [au] 3040 – 3180 – 3340
previous aphelion distance [103 au] 170 – 200 – 240
synchronous stop epoch [Myr] -3.35 S
percentage of VCs with qprev > 20100
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.
previous_g orbit statistics, here only the Galactic tide has been included
no. of returning VCs in the swarm 0
no. of escaping VCs in the swarm 5001 *
no. of hyperbolas among escaping VCs in the swarm 0
previous reciprocal semi-major axis [10-6 au-1] 4.88 – 6.92 – 8.85
previous perihelion distance [au] 40.9 – 44.5 – 48.4
previous aphelion distance [103 au] 230 – 290 – 410
synchronous stop epoch [Myr] -3.33 S
percentage of VCs with qprev > 20100