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
previous orbit statistics, both Galactic and stellar perturbations were taken into account
no. of returning VCs in the swarm 3622 *
no. of escaping VCs in the swarm 1379
no. of hyperbolas among escaping VCs in the swarm 1355
previous reciprocal semi-major axis [10-6 au-1] -711.82 – 647.40 – 1,997.61
previous perihelion distance [au] 1.2299 – 1.2316 – 1.2318 R
previous aphelion distance [103 au] 0.91 – 1.9 – 9
time interval to previous perihelion [Myr] 0.0095 – 0.03 – 0.28 R
percentage of VCs with qprev < 1098
percentage of VCs with qprev > 202
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 3617 *
no. of escaping VCs in the swarm 1384
no. of hyperbolas among escaping VCs in the swarm 1355
previous reciprocal semi-major axis [10-6 au-1] -711.83 – 647.40 – 1,997.61
previous perihelion distance [au] 1.2303 – 1.2317 – 1.2318 R
previous aphelion distance [103 au] 0.91 – 1.9 – 9
time interval to previous perihelion [Myr] 0.0095 – 0.029 – 0.28 R
percentage of VCs with qprev < 10100