C/1973 E1 Kohoutek
more info
Comet C/1973 E1 was discovered on 7 March 1973 by Luboš Kohoutek (Hamburg Observatory, Bergerdorf, Germany), that is 9 months and 3 weeks before its perihelion passage.Later, a prediscovery observation was found taken on 28 January at the same place. This comet was observed until 10 November 1974 [Kronk, Cometography: Volume 5].
Comet had its closest approach to the Earth on 15 January 1974 (0.806 au), 2.5 weeks after its perihelion passage.
Solution given here is based on data spanning over 1.24 yr in a range of heliocentric distances: 5.15 au – 0.142 au (perihelion) – 2.52 au.
This Oort spike comet suffers rather small planetary perturbations during its passage through the planetary system; these perturbations lead to a more tight future orbit with semimajor axis of about 1,700 au.
See also Królikowska 2020.

solution description
number of observations 850
data interval 1973 01 28 – 1974 04 26
data type perihelion within the observation arc (FULL)
data arc selection entire data set (STD)
range of heliocentric distances 5.15 au – 0.14 au (perihelion) – 2.52 au
type of model of motion NS - non-gravitational orbits for standard g(r)
data weighting YES
number of residuals 1690
RMS [arcseconds] 1.36
orbit quality class 2a
orbital elements (heliocentric ecliptic J2000)
Epoch 1973 12 24
perihelion date 1973 12 28.43058719 ± 0.00004303
perihelion distance [au] 0.14242263 ± 0.00000378
eccentricity 0.99999766 ± 0.00001781
argument of perihelion [°] 37.792322 ± 0.001934
ascending node [°] 258.495486 ± 0.001500
inclination [°] 14.303813 ± 0.000118
recip semi-major axis [10-6 au-1] 16.46 ± 125.06
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
non-gravitational parameters
A1 [10-8au\day-2] 0.23729 ± 0.39863
A2 [10-8au\day-2] -0.031613 ± 0.011024
A3 [10-8au\day-2] -0.4033 ± 0.10609
m -2.15
n 5.093
k -4.6142
r0 [au] 2.808
α 0.1113