C/1993 A1 Mueller
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Comet C/1993 A1 was discovered on 2 January 1993 by Jean Mueller (Palomar Sky Survey II). Later, a prediscovery image of this comet taken on 26 November 1992 (Catalina Station, Tucson) was found.At the moment of discovery, this comet was a year before its perihelion passage and it was last observed in the mid-August 1994.
Comet had its closest approach to the Earth on 13 November 1993 (1.713 au), 2 months before its perihelion passage.
This is a comet with nongravitational effects strongly manifested in positional data fitting.
Preferred solution given here is based on data spanning over 1.72 yr in a range of heliocentric distances: 4.89 au – 1.94 au (perihelion) – 3.19 au.
This Oort spike comet suffers moderate planetary perturbations during its passage through the planetary system; these perturbations lead to escape the comet on hyperbolic orbit from the planetary zone.See also Królikowska 2020.

solution description
number of observations 739
data interval 1992 11 26 – 1994 08 17
data type perihelion within the observation arc (FULL)
data arc selection entire data set (STD)
range of heliocentric distances 4.89 au – 1.94 au (perihelion) – 3.19 au
type of model of motion CT - non-gravitational orbits for assymetric CO-g(r)-like function
data weighting YES
number of residuals 1467
RMS [arcseconds] 0.87
orbit quality class 1a
orbital elements (barycentric ecliptic J2000)
Epoch 2288 03 07
perihelion date 1994 01 13.98280243 ± 0.00123080
perihelion distance [au] 1.93422556 ± 0.00002702
eccentricity 1.00099291 ± 0.00000912
argument of perihelion [°] 130.703900 ± 0.000752
ascending node [°] 144.875809 ± 0.000023
inclination [°] 124.891082 ± 0.000075
reciprocal semi-major axis [10-6 au-1] -513.33 ± 4.72
file containing 5001 VCs swarm
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.
Lower panel (panels): O-C diagram for this(two) solution (solutions) given in this database, where residuals in right ascension are shown using magenta dots and in declination by blue open circles.
Six 2D-projections of the 6D space of future swarm including 5001 VCs. Each density map is given in logarithmic scale presented on the right in the individual panel.