C/1993 K1 Shoemaker-Levy

Solar System
Dynamics &
Planetology
Group

General description

Few first positions of comet C/1993 K1 were measured by B. A. Skiff and C. S. Shoemaker from exposures taken by C. S. Shoemaker, E. M. Shoemaker and D. H. Levy (with the 0.46-m Schmidt telescope at Palomar) (IAUC 5808). At that moment the comet was more than eight months before its perihelion. Pre-discovery observations from March were found much later by M. Meyer.

The comet made its closest approach to the Earth on 6 May 1993 (4.35 au), that was 2.5 weeks before discovery. Similar close approach to the Earth was in the next opposition when the comet was within 4.48 au from the Earth (on 12 May 1994, about 3.5 months after perihelion passage).

Solution given below is based on data span over 2.9 yr in the range of heliocentric distances: 5.24 au – 4.85 au (perihelion) – 7.27 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 C1993K1A1-001

Comet C/1993 K1 Shoemaker-Levy

number of observations	44
number of residuals	86
data interval	1993 May 23 — 1996 Jan. 27
rms [arcsec]	1.02
orbit quality class	1a

Osculating orbital elements (heliocentric; ecliptic J2000.0)

Epoch (TT)	19940217.0	= JD 2449400.5
time of perihelion passage (TT)	19940201.947760	± 0.003910
perihelion distance	4.84927746	± 0.00002489
eccentricity	1.00023279	± 0.00003717
argument of perihelion [deg]	232.445275	± 0.000466
longitude of the ascending node [deg]	30.328581	± 0.000102
inclination [deg]	67.766928	± 0.000070
inverse semimajor axis [10^-6 au^-1]	-48.01	± 7.66

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

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/1993 K1. 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)	16881127
time of perihelion passage (TT)	19940131.665129	± 0.003962
perihelion distance	4.84471237	± 0.00002505
eccentricity	0.99985892	± 0.00003712
argument of perihelion [deg]	232.436917	± 0.000468
longitude of the ascending node [deg]	30.322178	± 0.000103
inclination [deg]	67.735390	± 0.000070
inverse semimajor axis [10^-6 au^-1]	29.12	± 7.66

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)	23060403
time of perihelion passage (TT)	19940201.616244	± 0.003885
perihelion distance	4.84606419	± 0.00002497
eccentricity	0.99711750	± 0.00003713
argument of perihelion [deg]	232.375367	± 0.000468
longitude of the ascending node [deg]	30.352470	± 0.000102
inclination [deg]	67.825586	± 0.000070
inverse semimajor axis [10^-6 au^-1]	594.81	± 7.66