C/1998 M3 Larsen

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C/1998 M3 Larsen

General description

Comet C/1998 M3 was discovered by J. Larsen on June 24 (two months before perihelion passage) but prediscovery observations made by LINEAR were found in images taken on May 26. Comet had its closest approach to Earth on 31 May 1998 (4.805 au) and was observed 1.1 yr in a range of heliocentric distances: 5.78 au – 5.77 au (perihelion) – 6.24 au.

C/1998 M3 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 C1998M3A5-001

Comet C/1998 M3 Larsen

number of observations	110
number of residuals	219
data interval	1998 May 26 — 1999 June 14
rms [arcsec]	0.66
orbit quality class	1b

Osculating orbital elements (heliocentric; ecliptic J2000.0)

Epoch (TT)	19980706.0	= JD 2451000.5
time of perihelion passage (TT)	19980717.141592	± 0.014729
perihelion distance	5.76830630	± 0.00004016
eccentricity	1.00222152	± 0.00003287
argument of perihelion [deg]	20.840919	± 0.001485
longitude of the ascending node [deg]	255.525387	± 0.000071
inclination [deg]	113.420178	± 0.000108
inverse semimajor axis [10^-6 au^-1]	-385.12	± 5.69

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/1998 M3. 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)	16900501
time of perihelion passage (TT)	19980715.793281	± 0.014631
perihelion distance	5.76636919	± 0.00003991
eccentricity	0.99916618	± 0.00003250
argument of perihelion [deg]	20.763331	± 0.001477
longitude of the ascending node [deg]	255.435959	± 0.000071
inclination [deg]	113.433778	± 0.000109
inverse semimajor axis [10^-6 au^-1]	144.60	± 5.64

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.

Figure caption: Six 2D-projections of the 6D space of future swarm (5001 VCs) of C/1998 M3. Each density map is given in logarithmic scale presented on the right in the individual panel.
The same figure in the new window

Future orbital elements (barycentric; at 250 au from the Sun)

Epoch (TT)	23070617
time of perihelion passage (TT)	19980715.578880	± 0.014663
perihelion distance	5.77023651	± 0.00003995
eccentricity	0.99881653	± 0.00003252
argument of perihelion [deg]	20.705550	± 0.001480
longitude of the ascending node [deg]	255.482996	± 0.000071
inclination [deg]	113.451985	± 0.000109
inverse semimajor axis [10^-6 au^-1]	205.10	± 5.64