C/1942 C2

Solar System
Dynamics &
Planetology
Group

C/1942 C2 Oterma

General description

Comet C/1942 C2 was discovered on 12 February 1942, about 7.5 months before perihelion passage and was last seen on 9 March 1943 [Kronk, Cometography: Volume 4].

This comet made its closest approach to the Earth on 29 December 1942 (3.21 au), that is three months after perihelion passage.

Solution given below is based on data span over 1.07 yr in a range of heliocentric distances from 4.53 au through perihelion (4.11 au) to 4.35 au.

Pure gravitational orbit determined from all available positional measurements (47 observations) give slightly hyperbolic original barycentric orbit (1b-class orbit); also original orbit given in Minor Planet Center is hyperbolic (35 obs. used, 2-days shorter arc of data; 1B-class orbit, see MPC).

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

More details in Królikowska et al. 2014, Królikowska and Dybczyński 2017

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 C1942C2A5-001

Comet C/1942 C2 Oterma

number of observations	47
number of residuals	88
data interval	1942 Feb. 12 — 1943 Mar. 11
rms [arcsec]	1.57
orbit quality class	1b

Osculating orbital elements (heliocentric; ecliptic J2000.0)

Epoch (TT)	19421008.0	= JD 2430640.5
time of perihelion passage (TT)	19420927.280025	± 0.007703
perihelion distance	4.11339144	± 0.00003196
eccentricity	1.00316671	± 0.00005609
argument of perihelion [deg]	163.620216	± 0.001441
longitude of the ascending node [deg]	281.038570	± 0.000853
inclination [deg]	172.514474	± 0.000124
inverse semimajor axis [10^-6 au^-1]	-769.85	± 13.62

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/1942 C2. 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)	16390708
time of perihelion passage (TT)	19420928.842884	± 0.007726
perihelion distance	4.10696133	± 0.00003147
eccentricity	1.00011952	± 0.00005530
argument of perihelion [deg]	163.752994	± 0.001446
longitude of the ascending node [deg]	281.002773	± 0.000850
inclination [deg]	172.517772	± 0.000123
inverse semimajor axis [10^-6 au^-1]	-29.10	± 13.47

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/1942 C2. 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)	22430304
time of perihelion passage (TT)	19420925.248677	± 0.007698
perihelion distance	4.10166979	± 0.00003144
eccentricity	1.00114131	± 0.00005527
argument of perihelion [deg]	163.296372	± 0.001447
longitude of the ascending node [deg]	281.066902	± 0.000849
inclination [deg]	172.512207	± 0.000123
inverse semimajor axis [10^-6 au^-1]	-278.25	± 13.47