C/1975 E1 Bradfield
more info
Comet C/1975 E1 was discovered on 12 March 1975 by William A. Bradfield (Dernancourt, South Australia, Australia), that is about 3 weeks before its perihelion passage.This comet was observed until 5 April 1976. [Kronk, Cometography: Volume 6].
Comet had its closest approach to the Earth on 19 April 1975 (1.838 au), about 2 weeks after its perihelion passage.
Solution given here is based on data spanning over 0.977 yr in a range of heliocentric distances: 1.26 au – 1.217 au (perihelion) – 4.44 au.
This Oort spike comet suffers large planetary perturbations during its passage through the planetary system; these perturbations lead to escape the comet from the solar system on hyperbolic orbit.
See also Królikowska 2020.

solution description
number of observations 54
data interval 1975 03 15 – 1976 03 07
data type significantly more measurements after perihelion (POST+)
data arc selection entire data set (STD)
range of heliocentric distances 1.26 au – 1.22 au (perihelion) – 4.44 au
detectability of NG effects in the comet's motion NG effects not determinable
type of model of motion GR - gravitational orbit
data weighting NO
number of residuals 108
RMS [arcseconds] 1.54
orbit quality class 2a
orbital elements (barycentric ecliptic J2000)
Epoch 2264 11 08
perihelion date 1975 04 05.22212819 ± 0.00098516
perihelion distance [au] 1.21519579 ± 0.00000825
eccentricity 1.00101674 ± 0.00003068
argument of perihelion [°] 264.083561 ± 0.001128
ascending node [°] 157.944649 ± 0.000157
inclination [°] 55.241434 ± 0.00014
reciprocal semi-major axis [10-6 au-1] -836.69 ± 25.24
file containing 5001 VCs swarm
1975e1a1.bpl
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.
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.