C/1999 J2 Skiff

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C/1999 J2 Skiff

General description

C/1999 J2 was discovered by B. Skiff of Lowell Observatory Near-Earth Object Search (LONEOS) team on 13 May 1999, 0.92 yr before perihelion passage.

This comet made its closest approach to Earth on 11 May 2000 (6.515 au), about one months after perihelion.

Solution given below is based on data span over 4.1 yr in a range of heliocentric distances: 7.42 au – 7.110 au (perihelion) – 10.1 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 C1999J2A2-001

Comet C/1999 J2 Skiff

number of observations	1001
number of residuals	1974
data interval	1999 May 12 — 2003 May 29
rms [arcsec]	0.53
orbit quality class	1a+

Osculating orbital elements (heliocentric; ecliptic J2000.0)

Epoch (TT)	20000406.0	= JD 2451640.5
time of perihelion passage (TT)	20000406.004255	± 0.000912
perihelion distance	7.10975456	± 0.00000468
eccentricity	1.00103030	± 0.00000456
argument of perihelion [deg]	127.140062	± 0.000063
longitude of the ascending node [deg]	50.042583	± 0.000012
inclination [deg]	86.412706	± 0.000009
inverse semimajor axis [10^-6 au^-1]	-144.91	± 0.64

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/1999 J2. 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)	16910317
time of perihelion passage (TT)	20000405.275717	± 0.000916
perihelion distance	7.11363383	± 0.00000474
eccentricity	0.99984298	± 0.00000460
argument of perihelion [deg]	127.111565	± 0.000063
longitude of the ascending node [deg]	50.100055	± 0.000011
inclination [deg]	86.368939	± 0.000009
inverse semimajor axis [10^-6 au^-1]	22.07	± 0.65

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)	23080103
time of perihelion passage (TT)	20000405.791060	± 0.000913
perihelion distance	7.11244479	± 0.00000475
eccentricity	1.00061909	± 0.00000460
argument of perihelion [deg]	127.109177	± 0.000063
longitude of the ascending node [deg]	50.076690	± 0.000011
inclination [deg]	86.364147	± 0.000009
inverse semimajor axis [10^-6 au^-1]	-87.04	± 0.65