Solar System
Dynamics &
Planetology
Group 		C/1947 S1 Bester



General description

data set of C/1947 S1

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Comet C/1947 S1 was discovered on 25 September 1947, that is about 4.7 months before perihelion passage, and was last seen on 6 February 1949 [Kronk, Cometography: Volume 4].

This comet made its closest approach to the Earth on 5 April 1948 (0.740 au), that is about 1.5 month after its perihelion passage.

Solution given below is based on data span over 1.356 yr in a range of heliocentric distances from 2.449 au through perihelion (0.748 au) to 4.890 au.

Pure gravitational orbit determined from the available positional measurements (325 observations) give 1a-class orbit.

It was possible to determine the non-gravitational orbit for C/1947 S1 where a small decrease of RMS was obtained (from 2.59 arcsec to 2.42 arcsec, see below).

Comet suffered moderate 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 orbits given below for both models of motion).

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 C1947S1N5-001

SSDP Cometary Note C1947S1A5-001

Comet C/1947 S1 Bester

number of observations 325
number of residuals 546
data interval 1947 Sep. 28 — 1949 Feb. 6
rms [arcsec] 2.59
orbit quality class 1a

Osculating orbital elements (heliocentric; ecliptic J2000.0)

Epoch (TT) 19480219.0 = JD 2432600.5
time of perihelion passage (TT) 19480216.423429 ± 0.000066
perihelion distance 0.74812370 ± 0.00000075
eccentricity 1.00035570 ± 0.00000258
argument of perihelion [deg] 350.214858 ± 0.000179
longitude of the ascending node [deg] 271.439960 ± 0.000229
inclination [deg] 140.568349 ± 0.000078
inverse semimajor axis [10-6 au-1] -475.46 ± 3.45

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



data set of C/1947 S1

Figure caption: Six 2D-projections of the 6D space of original swarm (5001 VCs) of C/1947 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) 16500111
time of perihelion passage (TT) 19480217.010780 ± 0.000061
perihelion distance 0.74919707 ± 0.00000076
eccentricity 0.99997502 ± 0.00000259
argument of perihelion [deg] 350.249194 ± 0.000181
longitude of the ascending node [deg] 271.413569 ± 0.000231
inclination [deg] 140.601343 ± 0.000079
inverse semimajor axis [10-6 au-1] 33.34 ± 3.46

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/1947 S1

Figure caption: Six 2D-projections of the 6D space of future swarm (5001 VCs) of C/1947 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) 22411219
time of perihelion passage (TT) 19480216.805182 ± 0.000086
perihelion distance 0.74487969 ± 0.00000076
eccentricity 1.00026541 ± 0.00000258
argument of perihelion [deg] 350.247822 ± 0.000181
longitude of the ascending node [deg] 271.579999 ± 0.000231
inclination [deg] 140.472078 ± 0.000079
inverse semimajor axis [10-6 au-1] -356.31 ± 3.46


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 C1947S1N5-001

number of observations 325
number of residuals 543
data interval 1947 Sep. 28 — 1949 Feb. 6
rms [arcsec] 2.42
orbit quality class 1b

Osculating orbital elements (heliocentric; ecliptic J2000.0)

Epoch (TT) 19480219.0 = JD 2432600.5
time of perihelion passage (TT) 19480216.422309 ± 0.000138
perihelion distance 0.74810617 ± 0.00000196
eccentricity 1.00023485 ± 0.00001240
argument of perihelion [deg] 350.213385 ± 0.000206
longitude of the ascending node [deg] 271.439361 ± 0.000208
inclination [deg] 140.568516 ± 0.000062
inverse semimajor axis [10-6 au-1] -313.92 ± 16.58

Nongravitational parameters [10-8 au/day2] A1 = 2.055 ± 0.207 A2 = -0.2341 ± 0.0649 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/1947 S1

Figure caption: Six 2D-projections of the 6D space of original swarm (5001 VCs) of C/1947 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) 16491023
time of perihelion passage (TT) 19480217.009294 ± 0.000304
perihelion distance 0.74915527 ± 0.00000502
eccentricity 0.99996030 ± 0.00000614
argument of perihelion [deg] 350.251157 ± 0.000340
longitude of the ascending node [deg] 271.412966 ± 0.000207
inclination [deg] 140.601506 ± 0.000062
inverse semimajor axis [10-6 au-1] 52.99 ± 8.19

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/1947 S1

Figure caption: Six 2D-projections of the 6D space of future swarm (5001 VCs) of C/1947 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) 22420925
time of perihelion passage (TT) 19480216.803521 ± 0.000310
perihelion distance 0.74482539 ± 0.00000549
eccentricity 1.00020675 ± 0.00000870
argument of perihelion [deg] 350.241846 ± 0.000620
longitude of the ascending node [deg] 271.579407 ± 0.000206
inclination [deg] 140.472235 ± 0.000061
inverse semimajor axis [10-6 au-1] -277.59 ± 11.68


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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