Solar System
Dynamics &
Planetology
Group 		C/1987 F1 Torres




data set of C/1987 F1

The same figure in the new window

General description


Comet C/1987 F1 was discovered by Carlos Torres (at Cerro El Roble) on 28 March 1987 (IAUC 4355), two weeks before its perihelion passage. The comet was last seen on 27 December 1989.

The comet made its closest approach to the Earth on 24 April 1984 (2.73 au), that was two weeks after its perihelion passage.

Solution given below is based on data span over 2.75 yr in the range of heliocentric distances: 3.63 au – 3.62 au (perihelion) – 8.75 au.


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 C1987F1A1-001

Comet C/1987 F1 Torres

number of observations 56
number of residuals 108
data interval 1987 Mar. 28 — 1989 Dec. 27
rms [arcsec] 1.14
orbit quality class 1a

Osculating orbital elements (heliocentric; ecliptic J2000.0)

Epoch (TT) 19870326.0 = JD 2446880.5
time of perihelion passage (TT) 19870410.278029 ± 0.002348
perihelion distance 3.62460449 ± 0.00001506
eccentricity 1.00101531 ± 0.00001802
argument of perihelion [deg] 329.089760 ± 0.000451
longitude of the ascending node [deg] 194.487714 ± 0.000055
inclination [deg] 124.079942 ± 0.000075
inverse semimajor axis [10-6 au-1] -280.12 ± 4.97

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

data set of C/1987 F1

Figure caption: Six 2D-projections of the 6D space of original swarm (5001 VCs) of C/1987 F1. 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) 16831114
time of perihelion passage (TT) 19870409.792606 ± 0.002309
perihelion distance 3.62427914 ± 0.00001504
eccentricity 0.99978940 ± 0.00001801
argument of perihelion [deg] 329.061349 ± 0.000450
longitude of the ascending node [deg] 194.483295 ± 0.000055
inclination [deg] 124.014019 ± 0.000076
inverse semimajor axis [10-6 au-1] 58.11 ± 4.97

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.

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

Epoch (TT) 22920106
time of perihelion passage (TT) 19870409.819196 ± 0.002347
perihelion distance 3.62589912 ± 0.00001498
eccentricity 0.99936819 ± 0.00001802
argument of perihelion [deg] 329.012173 ± 0.000450
longitude of the ascending node [deg] 194.474308 ± 0.000055
inclination [deg] 124.059494 ± 0.000076
inverse semimajor axis [10-6 au-1] 174.25 ± 4.97


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, 2013. All rights reserved

\