C/1971 E1 Toba
more info
Comet C/1971 E1 was discovered on 7 March 1971 by Kenji Toba (Tsuchiura, Ibaraki, Japan), that is more than a month before its perihelion passage. It was observed until 9 September 1971 [Kronk, Cometography: Volume 5].
Comet had its closest approach to the Earth on 9 June 1971 (0.724 au), about a month and 3 weeks after its perihelion passage.
Solutions given here are based on data spanning over 0.504 yr in a range of heliocentric distances: 1.37 au – 1.233 au (perihelion) – 2.41 au.
This comet suffers moderate planetary perturbations during its passage through the planetary system; according to preferred solution these perturbations lead to escape the comet from the planetary zone on a hyperbolic orbit (see future barycentric orbits).
See also Królikowska 2020.

solution description
number of observations 137
data interval 1971 03 09 – 1971 09 09
data type perihelion within the observation arc (FULL)
data arc selection entire data set (STD)
range of heliocentric distances 1.37 au – 1.23 au (perihelion) – 2.41 au
type of model of motion NS - non-gravitational orbits for standard g(r)
data weighting YES
number of residuals 275
RMS [arcseconds] 1.22
orbit quality class 2b
next orbit statistics, both Galactic and stellar perturbations were taken into account
no. of returning VCs in the swarm 2355
no. of escaping VCs in the swarm 2646
no. of hyperbolas among escaping VCs in the swarm 2510 *
next reciprocal semi-major axis [10-6 au-1] -276.99 – -0.85 – 274.36
next perihelion distance [au] 1.228 – 1.235 – 905.2 R
next aphelion distance [103 au] 5.8 – 13 – 76
time interval to next perihelion [Myr] 0.15 – 0.52 – 4 R
percentage of VCs with qnext < 1078
percentage of VCs with qnext > 2022
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.
next orbit statistics, here only the Galactic tide has been included
no. of returning VCs in the swarm 2343
no. of escaping VCs in the swarm 2658
no. of hyperbolas among escaping VCs in the swarm 2510 *
next reciprocal semi-major axis [10-6 au-1] -276.99 – -0.85 – 274.36
next perihelion distance [au] 1.231 – 1.24 – 2.912 R
next aphelion distance [103 au] 5.8 – 13 – 76
time interval to next perihelion [Myr] 0.15 – 0.51 – 4 R
percentage of VCs with qnext < 1095
percentage of VCs with 10 < qnext < 202
percentage of VCs with qnext > 203