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
previous orbit statistics, both Galactic and stellar perturbations were taken into account
no. of returning VCs in the swarm 3069 *
no. of escaping VCs in the swarm 1932
no. of hyperbolas among escaping VCs in the swarm 716
previous reciprocal semi-major axis [10-6 au-1] -5.32 – 26.67 – 58.81
previous perihelion distance [au] 0.35 – 160 – 270 R
previous aphelion distance [103 au] 33 – 65 – 230
time interval to previous perihelion [Myr] 1.9 – 3.6 – 10 R
percentage of VCs with qprev < 1024
percentage of VCs with 10 < qprev < 201
percentage of VCs with qprev > 2075
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.
previous orbit statistics, here only the Galactic tide has been included
no. of returning VCs in the swarm 3353 *
no. of escaping VCs in the swarm 1648
no. of hyperbolas among escaping VCs in the swarm 717
previous reciprocal semi-major axis [10-6 au-1] -5.36 – 26.65 – 58.81
previous perihelion distance [au] 0.12 – 2 – 360 R
previous aphelion distance [103 au] 33 – 65 – 230
time interval to previous perihelion [Myr] 1.9 – 4.3 – 10 R
percentage of VCs with qprev < 1061
percentage of VCs with 10 < qprev < 205
percentage of VCs with qprev > 2034