C/1940 S1

Solar System
Dynamics &
Planetology
Group

C/1940 S1 Okabyashi-Honda

General description

Comet C/1940 S1 was discovered on 30 September 1940, that is 1.5 month after perihelion passage, and was last seen on 3 January 1941 [Kronk, Cometography: Volume 4].

This comet made its closest approach to the Earth on 30 May 1940 (1.194 au), that is 4 months before its discovery.

Solution given below is based on data span over 0.249 yr in a range of heliocentric distances from 1.35 au to 2.38 au.

Comet suffered significant planetary perturbations during its passage through the planetary system that led to escape the comet from the planetary zone on a hyperbolic orbit (see future barycentric orbit given below).

More details in Królikowska et al. 2014

Figure caption: 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.

SSDP Cometary Note C1940S1A1-001

Comet C/1940 S1 Okabyashi-Honda

number of observations	38
number of residuals	61
data interval	1940 Oct. 4 — 1941 Jan. 3
rms [arcsec]	3.67
orbit quality class	2b

Osculating orbital elements (heliocentric; ecliptic J2000.0)

Epoch (TT)	19400730.0	= JD 2429840.5
time of perihelion passage (TT)	19400815.741520	± 0.018720
perihelion distance	1.06134353	± 0.00042312
eccentricity	1.00101170	± 0.00044419
argument of perihelion [deg]	329.641162	± 0.036347
longitude of the ascending node [deg]	128.060306	± 0.006071
inclination [deg]	133.112612	± 0.001116
inverse semimajor axis [10^-6 au^-1]	-953.22	± 418.31

Note: Epoch is given in a format: yyyymmdd.d, time of perihelion passage in a format of yyyymmdd.dddddd.

Figure caption: Six 2D-projections of the 6D space of original swarm (5001 VCs) of C/1940 S1. Each density map is given in logarithmic scale presented on the right in the individual panel.
The same figure in the new window

Original orbital elements (barycentric; at 250 au from the Sun)

Epoch (TT)	16381220
time of perihelion passage (TT)	19400816.604848	± 0.016028
perihelion distance	1.06507308	± 0.00043378
eccentricity	0.99968363	± 0.00045462
argument of perihelion [deg]	329.678357	± 0.037246
longitude of the ascending node [deg]	128.069124	± 0.006471
inclination [deg]	133.275676	± 0.000940
inverse semimajor axis [10^-6 au^-1]	297.04	± 426.96

Note: Values of uncertainties of original/future orbital elements were derived using a swarm of 5001 osculating orbits of VCs (including the nominal osculating orbit given above) for original/future orbital evolution calclulations and then by fitting the distribution of a given orbital element of original/future swarm of VCs to Gaussian distribution.

Original barycentric positions and velocities of 5001 VCs at 250 au from the Sun are given here (data format), i.e. before entering the planetary zone.

Figure caption: Six 2D-projections of the 6D space of future swarm (5001 VCs) of C/1940 S1. Each density map is given in logarithmic scale presented on the right in the individual panel.
The same figure in the new window

Future orbital elements (barycentric; at 250 au from the Sun)

Epoch (TT)	22310506
time of perihelion passage (TT)	19400816.426110	± 0.020136
perihelion distance	1.05927916	± 0.00042722
eccentricity	1.00074474	± 0.00045233
argument of perihelion [deg]	329.790299	± 0.036974
longitude of the ascending node [deg]	128.282572	± 0.006163
inclination [deg]	133.042273	± 0.001158
inverse semimajor axis [10^-6 au^-1]	-703.06	± 426.73