C/2020 S4 PanSTARRS
more info
Comet C/2020 S4 was discovered on 16 September 2020, about 2.5 yr before its perihelion passage. This comet was observed until 5 June 2024 (as in February 2025).

Comet had its closest approach to the Earth on 6 February 2023 (2.39 au); about 3 days before the perihelion passage.

Currently, the preferred NG solution given here is based on data span over 3.65 yr in a range of heliocentric distances: 8.04 au – 3.37 au (perihelion) – 5.29 au. This comet shows large trends in the O-C distribution for a purely gravitational orbit, which are substantially reduced when NG acceleration is included in the model of motion. Orbits based on pre-perihelion and post-perihelion data independently were also obtained.

This Oort spike comet suffers moderate planetary perturbations during its passage through the planetary system that lead to escape this comet from the solar system on hyperbolic orbit.
solution description
number of observations 1910
data interval 2020 09 16 – 2024 06 05
data type perihelion within the observation arc (FULL)
data arc selection entire data set (STD)
range of heliocentric distances 8.04 au – 3.37 au (perihelion) – 5.29 au
type of model of motion NS - non-gravitational orbits for standard g(r)
data weighting YES
number of residuals 3740
RMS [arcseconds] 0.39
orbit quality class 1a+
orbital elements (heliocentric ecliptic J2000)
Epoch 2023 02 25
perihelion date 2023 02 09.21956462 ± 0.00008624
perihelion distance [au] 3.36975354 ± 0.00000145
eccentricity 1.00112965 ± 0.00000151
argument of perihelion [°] 20.987031 ± 0.000024
ascending node [°] 117.721543 ± 0.000009
inclination [°] 20.56979 ± 0.000004
reciprocal semi-major axis [10-6 au-1] -335.23 ± 0.45
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).
non-gravitational parameters
A1 [10-8au/day2] 1991.6 ± 29.6
A2 [10-8au/day2] -920.03 ± 23.07
A3 [10-8au/day2] -0.7497 ± 5.1097
m -2.15
n 5.093
k -4.6142
r0 [au] 2.808
α 0.1113