Solar System
Dynamics &
Planetology
Group 		C/1940 R2 Cunningham




data set of C/1940 R2

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General description

Comet C/1940 R2 was discovered on 5 September 1940, about 4.3 months before its perihelion passage, and was last seen on 17 June 1941 [Kronk, Cometography: Volume 4]. Soon after, a prediscovery images on plates exposed on 25 August were found.

This comet made its closest approach to the Earth on 10 January 1941 (0.595 au), that is 6 days before perihelion passage.

Solution given below is based on data span over 0.600 yr in a range of heliocentric distances from 2.706 au through perihelion (0.368 au) to 1.665 au.

Pure gravitational orbit determined from all available positional measurements (370 observations) give 1b-class orbit similarly as in Minor Planet Center (189 obs. used, arc of data longer about 1.5 months; 1B class, see MPC, however, solution presented here give hyperbolic original orbit.

It was possible to determine the non-gravitational orbit for C/1940 R2 where a significant decrease of RMS was obtained (from 1.77 arcsec to 1.44 arcsec, see below) and in this model original semimajor axis placed this comet within the Oort spike.

Comet suffered large planetary perturbations during its passage through the planetary system, and they led to escape the comet from the planetary zone on a hyperbolic orbit (see future barycentric orbits in both solutions 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.



Non–gravitational orbit — see below SSDP Cometary Note C1940R2N1-001

SSDP Cometary Note C1940R2A1-001

Comet C/1940 R2 Cunningham

number of observations 370
number of residuals 678
data interval 1940 Aug. 25 — 1941 Apr. 1
rms [arcsec] 1.77
orbit quality class 1b

Osculating orbital elements (heliocentric; ecliptic J2000.0)

Epoch (TT) 19410106.0 = JD 2430000.5
time of perihelion passage (TT) 19410116.233869 ± 0.000068
perihelion distance 0.36774076 ± 0.00000272
eccentricity 1.00050751 ± 0.00000650
argument of perihelion [deg] 199.568992 ± 0.000117
longitude of the ascending node [deg] 296.590441 ± 0.000141
inclination [deg] 49.894827 ± 0.000173
inverse semimajor axis [10-6 au-1] -1380.07 ± 17.68

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



data set of C/1940 R2

Figure caption: Six 2D-projections of the 6D space of original swarm (5001 VCs) of C/1940 R2. Each density map is given in logarithmic scale presented on the right in the individual panel.
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Original orbital elements (barycentric; at 250 au from the Sun)

Epoch (TT) 16440830
time of perihelion passage (TT) 19410115.973517 ± 0.000159
perihelion distance 0.36427644 ± 0.00000282
eccentricity 1.00002186 ± 0.00000646
argument of perihelion [deg] 199.546182 ± 0.000115
longitude of the ascending node [deg] 296.892318 ± 0.000141
inclination [deg] 50.185071 ± 0.000168
inverse semimajor axis [10-6 au-1] -60.01 ± 17.74

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.



data set of C/1940 R2

Figure caption: Six 2D-projections of the 6D space of future swarm (5001 VCs) of C/1940 R2. 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) 22210806
time of perihelion passage (TT) 19410115.372565 ± 0.000073
perihelion distance 0.37020628 ± 0.00000271
eccentricity 1.00060367 ± 0.00000657
argument of perihelion [deg] 199.642916 ± 0.000117
longitude of the ascending node [deg] 296.590685 ± 0.000141
inclination [deg] 49.670477 ± 0.000171
inverse semimajor axis [10-6 au-1] -1630.62 ± 17.75


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



Non–gravitational orbit


SSDP Cometary Note C1940R2N1-001

number of observations 370
number of residuals 670
data interval 1940 Aug. 25 — 1941 Apr. 1
rms [arcsec] 1.49
orbit quality class 2a

Osculating orbital elements (heliocentric; ecliptic J2000.0)

Epoch (TT) 19410106.0 = JD 2430000.5
time of perihelion passage (TT) 19410116.234772 ± 0.000092
perihelion distance 0.36774724 ± 0.00000232
eccentricity 1.00040431 ± 0.00001067
argument of perihelion [deg] 199.570995 ± 0.000226
longitude of the ascending node [deg] 296.590817 ± 0.000180
inclination [deg] 49.893846 ± 0.000157
inverse semimajor axis [10-6 au-1] -1099.42 ± 29.03

Nongravitational parameters [10-8 au/day2] A1 = 1.426 ± 0.155 A2 = -0.0396 ± 0.0598 A3 = 0.0 (assumed)

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



data set of C/1940 R2

Figure caption: Six 2D-projections of the 6D space of original swarm (5001 VCs) of C/1940 R2. 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) 16430617
time of perihelion passage (TT) 19410115.973647 ± 0.000186
perihelion distance 0.36427385 ± 0.00000275
eccentricity 0.99998121 ± 0.00000624
argument of perihelion [deg] 199.547949 ± 0.000223
longitude of the ascending node [deg] 296.892704 ± 0.000181
inclination [deg] 50.184132 ± 0.000151
inverse semimajor axis [10-6 au-1] 51.59 ± 17.12

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.



data set of C/1940 R2

Figure caption: Six 2D-projections of the 6D space of future swarm (5001 VCs) of C/1940 R2. 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) 22221129
time of perihelion passage (TT) 19410115.373155 ± 0.000183
perihelion distance 0.37020004 ± 0.00000311
eccentricity 1.00055310 ± 0.00001323
argument of perihelion [deg] 199.639408 ± 0.000646
longitude of the ascending node [deg] 296.591043 ± 0.000184
inclination [deg] 49.669507 ± 0.000154
inverse semimajor axis [10-6 au-1] -1494.06 ± 35.72


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





Solar System Dynamics & Planetology Group, 2014. All rights reserved

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