C/2005 G1 LINEAR

Solar System
Dynamics &
Planetology
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C/2005 G1 LINEAR

General description

C/2005 G1 was discovered on 1 April 2005 by the LINEAR as an apparently asteroidal object. Its cometary apperance was reported three days later by C. Hergenrother using 1.54-m Kuiper reflector at Catalina. Prediscovery LINEAR detections from 22 March 2005 were also found [IAUC 8504, 2005 April 4].

This comet made its closest approach to Earth on 3 March 2006 (4.549 au), four days after perihelion.

Solution given below is based on data span over 2.0 yr in a range of heliocentric distances: 5.61 au – 4.961 au (perihelion) – 5.73 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 C2005G1_W-001

Comet C/2005 G1 LINEAR

number of observations	292
number of residuals	573
data interval	2005 Mar. 22 — 2007 Mar. 11
rms [arcsec]	0.49
orbit quality class	1a

Osculating orbital elements (heliocentric; ecliptic J2000.0)

Epoch (TT)	20060306.0	= JD 2453800.5
time of perihelion passage (TT)	20060227.383771	± 0.000994
perihelion distance	4.96067147	± 0.00000433
eccentricity	0.99979762	± 0.00000508
argument of perihelion [deg]	113.825055	± 0.000120
longitude of the ascending node [deg]	299.586688	± 0.000029
inclination [deg]	108.414423	± 0.000010
inverse semimajor axis [10^-6 au^-1]	40.80	± 1.02

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/2005 G1. 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)	17001215
time of perihelion passage (TT)	20060226.533616	± 0.000969
perihelion distance	4.95322048	± 0.00000434
eccentricity	0.99991785	± 0.00000505
argument of perihelion [deg]	113.858813	± 0.000118
longitude of the ascending node [deg]	299.571155	± 0.000029
inclination [deg]	108.385968	± 0.000009
inverse semimajor axis [10^-6 au^-1]	16.58	± 1.02

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)	23111103
time of perihelion passage (TT)	20060227.214273	± 0.000986
perihelion distance	4.95699500	± 0.00000428
eccentricity	0.99976267	± 0.00000506
argument of perihelion [deg]	113.727471	± 0.000118
longitude of the ascending node [deg]	299.558608	± 0.000029
inclination [deg]	108.370283	± 0.000010
inverse semimajor axis [10^-6 au^-1]	47.88	± 1.02