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
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 1321
RMS [arcseconds] 0.54
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] 17.94 – 18.68 – 19.41
previous perihelion distance [au] 4100 – 4460 – 4900
previous aphelion distance [103 au] 99 – 103 – 107
time interval to previous perihelion [Myr] 10.7 – 11.4 – 12
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 4574 *
no. of escaping VCs in the swarm 427
no. of hyperbolas among escaping VCs in the swarm 0
previous reciprocal semi-major axis [10-6 au-1] 16.09 – 16.79 – 17.61 R
previous perihelion distance [au] 790 – 1000 – 1300 R
previous aphelion distance [103 au] 113 – 118 – 123 R
time interval to previous perihelion [Myr] 12.5 – 13.3 – 14 R
percentage of VCs with qprev > 20100