Solar System
Dynamics &
Planetology
Group 		C/2012 A1 PanSTARRS



data set of C/2012 A1

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General description

Comet C/2012 A1 was discovered 1.9 yr before perihelion passage and next observed 3.2 yr during four oppositions in a range of heliocentric distances: 8.73 au – 7.603 au (perihelion) – 8.12 au.

Comet had its closest approach to Earth on 22 December 2013 (6.642 au, almost three weeks after perihelion passage).

C/2012 A1 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 C2012A1A5-001

Comet C/2012 A1 PanSTARRS

number of observations 330
number of residuals 653
data interval 2012 Jan. 2 — 2015 Mar. 9
rms [arcsec] 0.40
orbit quality class 1a+

Osculating orbital elements (heliocentric; ecliptic J2000.0)

Epoch (TT) 20131214.0 = JD 2456640.5
time of perihelion passage (TT) 20131202.218131 ± 0.001173
perihelion distance 7.60253338 ± 0.00000787
eccentricity 1.00164070 ± 0.00000730
argument of perihelion [deg] 191.934807 ± 0.000071
longitude of the ascending node [deg] 277.971479 ± 0.000007
inclination [deg] 120.910023 ± 0.000014
inverse semimajor axis [10-6 au-1] -215.81 ± 0.96

Note: Epoch is given in a format: yyyymmdd.d, time of perihelion passage in a format of yyyymmdd.dddddd.
data set of C/2012 A1

Figure caption: Six 2D-projections of the 6D space of original swarm (5001 VCs) of C/2012 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) 17030514
time of perihelion passage (TT) 20131130.413300 ± 0.001163
perihelion distance 7.59939009 ± 0.00000784
eccentricity 0.99937163 ± 0.00000724
argument of perihelion [deg] 191.830837 ± 0.000071
longitude of the ascending node [deg] 277.961310 ± 0.000007
inclination [deg] 120.933007 ± 0.000014
inverse semimajor axis [10-6 au-1] 82.69 ± 0.95

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.





data set of C/2012 A1

Figure caption: Six 2D-projections of the 6D space of future swarm (5001 VCs) of C/2012 A1. 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) 23250602
time of perihelion passage (TT) 20131201.707717 ± 0.001164
perihelion distance 7.59862542 ± 0.00000785
eccentricity 0.99879397 ± 0.00000724
argument of perihelion [deg] 191.892635 ± 0.000071
longitude of the ascending node [deg] 277.978070 ± 0.000007
inclination [deg] 120.938298 ± 0.000014
inverse semimajor axis [10-6 au-1] 158.72 ± 0.95


Future barycentric positions and velocities of 5001 VCs at 250 au from the Sun are given here   (data format), i.e. after leaving the planetary zone.





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