C/2000 O1 Koehn

Solar System
Dynamics &
Planetology
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C/2000 O1 Koehn

General description

C/2000 O1 was discovered on 26 May 2000 by B.W Koehn in the course of the LONEOS as a cometary object [IAUC 7462, 2000 July 23]. Positional observations of this comet were next linked by B.G. Marsden with pre-discovery meeasurements of two asteroidal objects observed by LINEAR (1998 XA₇₀ = 1999 UJ₁₀) going back to 14 December 1998 [MPEC 2000-O22].

This comet made its closest approach to Earth on 9 November 1999 (5.050 au), 2.5 months before perihelion.

Solution given below is based on data span over 2.7 yr in a range of heliocentric distances: 6.58 au – 5.922 au (perihelion) – 7.15 au.

Comet suffered a very slight planetary perturbations during its passage through the planetary system.

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 C2000O1A1-001

Comet C/2000 O1 Koehn

number of observations	65
number of residuals	128
data interval	1998 Dec. 14 — 2001 Aug. 27
rms [arcsec]	0.81
orbit quality class	1a

Osculating orbital elements (heliocentric; ecliptic J2000.0)

Epoch (TT)	20000117.0	= JD 2451560.5
time of perihelion passage (TT)	20000127.393232	± 0.003402
perihelion distance	5.92165320	± 0.00002637
eccentricity	1.00069750	± 0.00002806
argument of perihelion [deg]	55.112765	± 0.000318
longitude of the ascending node [deg]	88.862048	± 0.000114
inclination [deg]	148.097534	± 0.000041
inverse semimajor axis [10^-6 au^-1]	-117.79	± 4.74

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/2000 O1. 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)	16920927
time of perihelion passage (TT)	20000128.212579	± 0.003342
perihelion distance	5.91487290	± 0.00002655
eccentricity	0.99969254	± 0.00002809
argument of perihelion [deg]	55.184190	± 0.000313
longitude of the ascending node [deg]	88.877691	± 0.000115
inclination [deg]	148.072564	± 0.000040
inverse semimajor axis [10^-6 au^-1]	51.98	± 4.75

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)	23080502
time of perihelion passage (TT)	20000127.073362	± 0.003379
perihelion distance	5.91375918	± 0.00002654
eccentricity	0.99925104	± 0.00002809
argument of perihelion [deg]	55.131151	± 0.000314
longitude of the ascending node [deg]	88.950073	± 0.000115
inclination [deg]	148.085030	± 0.000040
inverse semimajor axis [10^-6 au^-1]	126.65	± 4.75