C/2020 S4 PanSTARRS
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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.
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 | 992 | |
| data interval | 2020 09 16 – 2023 02 09 | |
| data arc selection | data generally limited to pre-perihelion (PRE) | |
| range of heliocentric distances | 8.04 au – 3.37 au (perihelion) – 3.37 au | |
| type of model of motion | NH - non-gravitational orbits for water sublimation from subsolar point | |
| data weighting | YES | |
| number of residuals | 1975 | |
| RMS [arcseconds] | 0.42 | |
| orbit quality class | 1a | |
| orbital elements (heliocentric ecliptic J2000) | ||
|---|---|---|
| Epoch | 2023 02 25 | |
| perihelion date | 2023 02 09.20308678 | ± 0.00302766 |
| perihelion distance [au] | 3.36981451 | ± 0.00000976 |
| eccentricity | 1.00119645 | ± 0.00001393 |
| argument of perihelion [°] | 20.982870 | ± 0.000685 |
| ascending node [°] | 117.722008 | ± 0.000027 |
| inclination [°] | 20.570469 | ± 0.000039 |
| reciprocal semi-major axis [10-6 au-1] | -355.05 | ± 4.13 |
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).
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] | 9.8549 | ± 0.5191 |
| A2 [10-8au/day2] | 0.97468 | ± 0.63028 |
| A3 [10-8au/day2] | 1.9566 | ± 0.1095 |
| m | -2.05 | |
| n | 3.070 | |
| k | -2,752.4000 | |
| r0 [au] | 50.000 | |
| α | 0.0003 | |