Solar System
Dynamics &
Planetology
Group 		C/2007 Q3 Siding Spring


General description

data set of C/2007 Q3
Visible trends in the O-C time variations for non-gravitational solutions (important normal component of nongravitational acceleration) based on entire data set were noticed. This comet should be examined in a special way. In the middle of March 2010, Nick Howes reported a small secondary piece of C/2007 Q3 on the picture taken using Faulkes Telescope North. The existence of this secondary component was later confirmed during the follow-up observations taken from March 17 up to April 9 by many other observers (see MPC IAU Circular 9135). Indeed, this period correlates with a time interval where significant trends in both right ascension and in declination appear in the O-C diagrams even in the non-gravitational model of motion; see O-C time variation corresponding to light grey part of data shown in the top panel of the figure given on the right.

Thus, here two types of solutions are given: This second type of solutions for backward and forward dynamical studies is recommended.
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; time interval, where the O-C diagram for the non-gravitational solution (middle panel) give significant trends in right ascension and declination is shown in light grey – this period correlates with the moment when a secondary fragment broke away from the nucleus. The same figure in the new window



SSDP Cometary Note C2007Q3N6-001

Comet C/2007 Q3 Siding Spring (non-gravitational solution)

number of observations 1368
number of residuals 2658
data interval 2007 Aug. 25 — 2011 Sep. 25
rms [arcsec] 0.39
orbit quality class 1a+

Osculating orbital elements (heliocentric; ecliptic J2000.0)

Epoch (TT) 20091016.0 = JD 2455120.5
time of perihelion passage (TT) 20091007.265422 ± 0.000050
perihelion distance 2.25169273 ± 0.00000065
eccentricity 1.00025939 ± 0.00000171
argument of perihelion[deg] 2.090436 ± 0.000012
longitude of the ascending node [deg] 149.412849 ± 0.000008
inclination[deg] 65.650440 ± 0.000005
inverse semimajor axis [10-6 au-1] -115.20 ± 0.76

Nongravitational parameters [10-8 au/day2] A1 = 0.156 ± 0.180 A2 = 2.675 ± 0.103 A3 = 1.657 ± 0.037

Note: Epoch is given in a format: yyyymmdd.d, time of perihelion passage in a format of yyyymmdd.dddddd.
data set of C/2007 Q3

Figure caption: Six 2D-projections of the 9D space of original swarm (5001 VCs) of C/2007 Q3. 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) 17081213.0
time of perihelion passage (TT) 20091007.093891 ± 0.000114
perihelion distance 2.25546432 ± 0.00000096
eccentricity 0.99991174 ± 0.00000111
argument of perihelion[deg] 2.067338 ± 0.000044
longitude of the ascending node [deg] 149.432081 ± 0.000011
inclination[deg] 65.620443 ± 0.000005
inverse semimajor axis [10-6 au-1] 39.13 ± 0.49

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/2007 Q3

Figure caption: Six 2D-projections of the 9D space of future swarm (5001 VCs) of C/2007 Q3. 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) 23110706.0
time of perihelion passage (TT) 20091007.623842 ± 0.000160
perihelion distance 2.25375096 ± 0.00000108
eccentricity 0.99973190 ± 0.00000215
argument of perihelion[deg] 2.092374 ± 0.000061
longitude of the ascending node [deg] 149.370279 ± 0.000007
inclination[deg] 65.647925 ± 0.000007
inverse semimajor axis [10-6 au-1] 118.96 ± 0.96


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.





SSDP Cometary Note C2007Q3PA-001

Comet C/2007 Q3 Siding Spring (solution based on pre-perihelion observations)

number of observations 568
number of residuals 1112
data interval 2007 Aug. 25 — 2009 Oct. 3 (pre-perihelion data)
rms [arcsec] 0.30
orbit quality class 1a+

Osculating orbital elements (heliocentric; ecliptic J2000.0)

Epoch (TT) 20091016.0 = JD 2455120.5
time of perihelion passage (TT) 20091007.267137 ± 0.000153
perihelion distance 2.25167770 ± 0.00000128
eccentricity 1.00022406 ± 0.00000119
argument of perihelion[deg] 2.091211 ± 0.000046
longitude of the ascending node [deg] 149.413010 ± 0.000013
inclination[deg] 65.650162 ± 0.000004
inverse semimajor axis [10-6 au-1] -99.51 ± 0.53

Note: Epoch is given in a format: yyyymmdd.d, time of perihelion passage in a format of yyyymmdd.dddddd.
Most recommended model for studying the origin of this comet.
data set of C/2007 Q3

Figure caption: Six 2D-projections of the 6D space of original swarm (5001 VCs) of C/2007 Q3. 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) 17081213.0
time of perihelion passage (TT) 20091007.094186 ± 0.000147
perihelion distance 2.25545290 ± 0.00000129
eccentricity 0.99990547 ± 0.00000116
argument of perihelion[deg] 2.067678 ± 0.000046
longitude of the ascending node [deg] 149.432150 ± 0.000012
inclination[deg] 65.620427 ± 0.000005
inverse semimajor axis [10-6 au-1] 41.91 ± 0.53

Note: Values of uncertainties of original orbital elements were derived using a swarm of 5001 osculating orbits of VCs (including the nominal osculating orbit given above) for original orbital evolution calclulations and then by fitting the distribution of a given orbital element of original 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.




SSDP Cometary Note C2007Q3RA-001

Comet C/2007 Q3 Siding Spring (solution based on post-perihelion observations)

number of observations 177
number of residuals 342
data interval 2010 June 8 — 2011 Sep. 25 (post-perihelion data)
rms [arcsec] 0.66
orbit quality class 1a

Osculating orbital elements (heliocentric; ecliptic J2000.0)

Epoch (TT) 20091016.0 = JD 2455120.5
time of perihelion passage (TT) 20091007.262200 ± 0.001604
perihelion distance 2.25171331 ± 0.00001520
eccentricity 1.00025450 ± 0.00000829
argument of perihelion[deg] 2.090673 ± 0.000332
longitude of the ascending node [deg] 149.412480 ± 0.000108
inclination[deg] 65.650754 ± 0.000025
inverse semimajor axis [10-6 au-1] -113.02 ± 3.68

Note: Epoch is given in a format: yyyymmdd.d, time of perihelion passage in a format of yyyymmdd.dddddd.
Most recommended model for studying the future evolution of this comet.

data set of C/2007 Q3

Figure caption: Six 2D-projections of the 6D space of future swarm (5001 VCs) of C/2007 Q3. 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) 23110815.0
time of perihelion passage (TT) 20091007.619323 ± 0.001618
perihelion distance 2.25376856 ± 0.00001552
eccentricity 0.99970301 ± 0.00000817
argument of perihelion[deg] 2.092267 ± 0.000334
longitude of the ascending node [deg] 149.369798 ± 0.000111
inclination[deg] 65.648034 ± 0.000025
inverse semimajor axis [10-6 au-1] 131.77 ± 3.63

Note: Values of uncertainties of future orbital elements were derived using a swarm of 5001 osculating orbits of VCs (including the nominal osculating orbit given above) for future orbital evolution calclulations and then by fitting the distribution of a given orbital element of future swarm of VCs to Gaussian distribution.

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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