Solar System
Dynamics &
Planetology
Group 		C/2009 R1 McNaught


General description

data set of C/2009 R1
This comet of a very small perihelion distance (qosc = 0.405 au) was observed only before its perihelion passage and was lost soon after it, some speculations about its disintegration were reported by some observers. Although only the pre-perihelion data are available, C/2009 R1 exhibits strong and well-determinable NG effects during interval covered by these positional measurements and the NG solution is given just below.

Some trends in O-C time variations for the pure gravitational model based on entire data set are clearly visible (see lowest panel of the figure on the right); O-C time variations for non-gravitational solution (middle panel on the right) are much better for both right ascension (magenta points) and declination (blue open circles).

More details in Królikowska and Dybczyński, 2013.



Figure caption: Upper panel: Time distribution of positional observations with corresponding heliocentric (red curve) and geocentric (green curve) distance at which they were taken. The horizontal dotted lines show the perihelion distance for a given comet whereas vertical dotted lines — the moment of perihelion passage. Lowest panel: O-C diagram for the gravitational solution shows significant trends in right ascension (magenta dots) and declination (blue open circles). These trends almost disapear for non-gravitational solution (middle panel) The same figure in the new window






SSDP Cometary Note C2009R1N5-001

Comet C/2009 R1 McNaught (non-gravitational solution)

number of observations 792
number of residuals 1501
data interval 2009 July 20 — 2010 June 29
rms [arcsec] 0.51
orbit quality class 1b

Osculating orbital elements (heliocentric; ecliptic J2000.0)

Epoch (TT) 20100411.0 = JD 2455297.5
time of perihelion passage (TT) 20100702.675680 ± 0.000232
perihelion distance 0.40501846 ± 0.00000260
eccentricity 1.00035977 ± 0.00000121
argument of perihelion [deg] 130.700102 ± 0.000199
longitude of the ascending node [deg] 322.622314 ± 0.000032
inclination [deg] 77.034327 ± 0.000192
inverse semimajor axis [10-6 au-1] -888.27 ± 2.98

Nongravitational parameters [10-8 au/day2] A1 = 5.798 ± 0.490 A2 = -1.418 ± 0.359 A3 = 0.776 ± 0.208

Note: Epoch is given in a format: yyyymmdd.d, time of perihelion passage in a format of yyyymmdd.dddddd.

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

Epoch (TT) 17130408
time of perihelion passage (TT) 20100701.169302 ± 0.000278
perihelion distance 0.39442252 ± 0.00000159
eccentricity 0.99999520 ± 0.00000130
argument of perihelion [deg] 131.134477 ± 0.000137
longitude of the ascending node [deg] 322.671047 ± 0.000036
inclination [deg] 77.008392 ± 0.000137
inverse semimajor axis [10-6 au-1] 12.16 ± 3.29

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) 23090802
time of perihelion passage (TT) 20100703.078964 ± 0.002045
perihelion distance 0.40705236 ± 0.00002438
eccentricity 0.99993062 ± 0.00008029
argument of perihelion [deg] 130.727483 ± 0.001900
longitude of the ascending node [deg] 322.607146 ± 0.000130
inclination [deg] 77.010035 ± 0.000107
inverse semimajor axis [10-6 au-1] 170.43 ± 197.26


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.





Solar System Dynamics & Planetology Group, 2013. All rights reserved

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