C/2005 L3 McNaught

Solar System
Dynamics &
Planetology
Group

C/2005 L3 McNaught

General description

C/2005 L3 was discovered by R.H. McNaught with the 0.5-m Uppsala Schmidt in the course of the Siding Spring Survey on 3 June 2005 [IAUC 8536, 2005 June 7]. Later, prediscovery detections by Siding Spring Survey were found (16 July and 16 August 2004).

This comet made its closest approaches to Earth on 24 June 2007 (4.852 au, almost seven months before perihelion) and 12 May 2008 (4.857 au, four months after perihelion).

Solution given below is based on data span over 8.7 yr in a range of heliocentric distances: 10.3 au – 5.593 au (perihelion) – 13.4 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 C2005L3A5-001

Comet C/2005 L3 McNaught

number of observations	5337
number of residuals	10503
data interval	2004 July 16 — 2013 Mar. 15
rms [arcsec]	0.49
orbit quality class	1a+

Osculating orbital elements (heliocentric; ecliptic J2000.0)

Epoch (TT)	20080115.0	= JD 2454480.5
time of perihelion passage (TT)	20080116.005851	± 0.000088
perihelion distance	5.59327050	± 0.00000047
eccentricity	0.99991033	± 0.00000071
argument of perihelion [deg]	47.096947	± 0.000009
longitude of the ascending node [deg]	288.739107	± 0.000004
inclination [deg]	139.448742	± 0.000002
inverse semimajor axis [10^-6 au^-1]	16.03	± 0.13

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 L3. 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)	17010305
time of perihelion passage (TT)	20080115.292269	± 0.000088
perihelion distance	5.58682654	± 0.00000053
eccentricity	0.99965548	± 0.00000070
argument of perihelion [deg]	47.073480	± 0.000009
longitude of the ascending node [deg]	288.707828	± 0.000004
inclination [deg]	139.391017	± 0.000002
inverse semimajor axis [10^-6 au^-1]	61.67	± 0.13

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)	23171002
time of perihelion passage (TT)	20080114.821598	± 0.000088
perihelion distance	5.58874050	± 0.00000040
eccentricity	0.99836758	± 0.00000070
argument of perihelion [deg]	47.063435	± 0.000009
longitude of the ascending node [deg]	288.804398	± 0.000004
inclination [deg]	139.445843	± 0.000002
inverse semimajor axis [10^-6 au^-1]	292.09	± 0.13