C/2000 A1 Montani

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Planetology
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C/2000 A1 Montani

General description

C/2000 A1 was discovered on 12 January 2000 by J. Montani on CCD images taken using the Spacewatch telescope at Kitt Peak as cometary object [IAUC 7346, 2000 January 14]. After preliminary orbit computations it was found that Spacewatch and LINEAR survey registered this object on pre-discovery images [for more discovery details see Spacewatch Web Page].

This comet made its closest approach to Earth on 20 January 2000 (8.809 au), 5.7 months before perihelion.

Solution given below is based on data span over 2.2 yr in a range of heliocentric distances: 9.80 au – 9.743 au (perihelion) – 10.3 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 C2001A1A2-001

Comet C/2000 A1 Montani

number of observations	132
number of residuals	264
data interval	2000 Jan. 4 — 2002 Mar. 20
rms [arcsec]	0.45
orbit quality class	1a

Osculating orbital elements (heliocentric; ecliptic J2000.0)

Epoch (TT)	20000625.0	= JD 2451720.5
time of perihelion passage (TT)	20000713.137414	± 0.011178
perihelion distance	9.74312736	± 0.00002922
eccentricity	1.00388320	± 0.00001921
argument of perihelion [deg]	14.265914	± 0.000509
longitude of the ascending node [deg]	111.835674	± 0.000042
inclination [deg]	24.542798	± 0.000049
inverse semimajor axis [10^-6 au^-1]	-398.56	± 1.97

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/2000 A1. 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)	16861029
time of perihelion passage (TT)	20000715.206584	± 0.011038
perihelion distance	9.74094723	± 0.00002930
eccentricity	0.99960423	± 0.00001927
argument of perihelion [deg]	14.342181	± 0.000503
longitude of the ascending node [deg]	111.888001	± 0.000041
inclination [deg]	24.552710	± 0.000049
inverse semimajor axis [10^-6 au^-1]	40.63	± 1.98

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)	23140908
time of perihelion passage (TT)	20000713.185351	± 0.011047
perihelion distance	9.74225531	± 0.00002926
eccentricity	0.99927460	± 0.00001927
argument of perihelion [deg]	14.319745	± 0.000504
longitude of the ascending node [deg]	111.847687	± 0.000041
inclination [deg]	24.549661	± 0.000049
inverse semimajor axis [10^-6 au^-1]	74.46	± 1.98