C/2004 P1 NEAT

Solar System
Dynamics &
Planetology
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C/2004 P1 NEAT

General description

C/2004 P1 was discovered on 5 August 2004 by the LINEAR as a faint diffuse comet. In the following days, its cometary apperance was confirmed [IAUC 8383, 2004 August 8]. Later, three pre-discovery detections by AMOS were found (11 May 2003, and 8, 21 July 2003).

This comet made its closest approach to Earth on 20 July 2003 (5.233 au), 19 days before perihelion.

Solution given below is based on data span over 2.3 yr in a range of heliocentric distances: 6.05 au – 6.014 au (perihelion) – 7.91 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 C2004P1A2-001

Comet C/2004 P1 NEAT

number of observations	151
number of residuals	298
data interval	2003 May 11 — 2005 Aug. 30
rms [arcsec]	0.63
orbit quality class	1a

Osculating orbital elements (heliocentric; ecliptic J2000.0)

Epoch (TT)	20030720.0	= JD 2452840.5
time of perihelion passage (TT)	20030808.923813	± 0.006332
perihelion distance	6.01409659	± 0.00003034
eccentricity	0.99873180	± 0.00001857
argument of perihelion [deg]	16.596434	± 0.000685
longitude of the ascending node [deg]	284.193932	± 0.000238
inclination [deg]	28.823571	± 0.000094
inverse semimajor axis [10^-6 au^-1]	210.87	± 3.09

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/2004 P1. 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)	16960509
time of perihelion passage (TT)	20030809.041740	± 0.006290
perihelion distance	6.02262457	± 0.00003005
eccentricity	0.99981290	± 0.00001835
argument of perihelion [deg]	16.535459	± 0.000689
longitude of the ascending node [deg]	284.228301	± 0.000240
inclination [deg]	28.798128	± 0.000095
inverse semimajor axis [10^-6 au^-1]	31.07	± 3.05

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)	23090606
time of perihelion passage (TT)	20030809.402431	± 0.006324
perihelion distance	6.01959208	± 0.00003012
eccentricity	1.00053526	± 0.00001833
argument of perihelion [deg]	16.663610	± 0.000687
longitude of the ascending node [deg]	284.176723	± 0.000240
inclination [deg]	28.802090	± 0.000095
inverse semimajor axis [10^-6 au^-1]	-88.92	± 3.05