Solar System
Dynamics &
Planetology
Group 		C/2007 W1 Boattini


General description

data set of C/2007 W1
Very strong trends in the O-C time variations even for asymmetric non-gravitational solution based on entire data set (SSDP Cometary Note C2007W1N6-001, see just below) are clearly visible in the middle panel of the figure given on the right. Therefore due to its erratic behaviour, this comet should be examined in a special way. Similarly as in Nakano Notes (NK1731A, NK1731B), two dedicated separate non-gravitational orbits should be determined (recommended for backward and forward dynamical studies, respectively).

Thus, here two types of solutions are given: This second type of solutions is recommended for studying the dynamical evolution of this comet.
More details in Królikowska and Dybczyński, 2013.

C/2007 W1 having a negative value of 1/aori for all types of solutions is an excellent candidate to be an interstellar comet.

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. Middle panel: O-C diagram for the non-gravitational solution shows significant trends in right ascension (magenta dots) and declination (blue open circles). These trends almost disapear for non-gravitational solutions (lowest panel) determined independently for pre- and post-perihelion data sets (SSDP Cometary Notes: C2007W1P5-001 and C2007W1R5-001, respectively) The same figure in the new window



SSDP Cometary Note C2007W1N6-001

Comet C/2007 W1 Boattini (asymmetric non-gravitational solution)

number of observations 1703
number of residuals 3293
data interval 2007 Nov. 20 — 2008 Dec. 17
rms [arcsec] 0.60
orbit quality class 1a

Osculating orbital elements (heliocentric; ecliptic J2000.0)

Epoch (TT) 20080623.0 = JD 2454640.5
time of perihelion passage (TT) 20080624.885133 ± 0.000007
perihelion distance 0.84967565 ± 0.00000012
eccentricity 1.00010098 ± 0.00000132
argument of perihelion[deg] 306.550830 ± 0.000026
longitude of the ascending node [deg] 334.523804 ± 0.000030
inclination[deg] 9.889166 ± 0.000010
inverse semimajor axis [10-6 au-1] -118.84 ± 1.56

Nongravitational parameters [10-8 au/day2] A1 = 3.97480 ± 0.00841 A2 = -0.4266 ± 0.0138 A3 = -0.06387 ± 0.00276
time shift of g(r) relative to perihelion [day] 24.7 ± 4.3

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) 17101203.0
time of perihelion passage (TT) 2008625.604804 ± 0.000034
perihelion distance 0.85571663 ± 0.00000021
eccentricity 1.00002492 ± 0.00000111
argument of perihelion[deg] 306.193581 ± 0.000036
longitude of the ascending node [deg] 334.735622 ± 0.000036
inclination[deg] 9.764012 ± 0.000012
inverse semimajor axis [10-6 au-1] -29.12 ± 1.30

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 W1

Figure caption: Six 2D-projections of the 10D space of future swarm (5001 VCs) of C/2007 W1. 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) 23120302.0
time of perihelion passage (TT) 20080624.796026 ± 0.000144
perihelion distance 0.84646901 ± 0.00000073
eccentricity 0.99957598 ± 0.00000363
argument of perihelion[deg] 306.418859 ± 0.000075
longitude of the ascending node [deg] 334.559057 ± 0.000031
inclination[deg] 9.892780 ± 0.000013
inverse semimajor axis [10-6 au-1] 500.93 ± 4.28


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 C2007W1P5

Comet C/2007 W1 Boattini (non-gravitational solution based on pre-perihelion data)

number of observations 926
number of residuals 1771
data interval 2007 Nov. 20 — 2008 June 12 (pre-perihelion data)
rms [arcsec] 0.49
orbit quality class 1b

Osculating orbital elements (heliocentric; ecliptic J2000.0)

Epoch (TT) 20080623.0 = JD 2454640.5
time of perihelion passage (TT) 20080624.887029 ± 0.000159
perihelion distance 0.84965694 ± 0.00000169
eccentricity 1.00011020 ± 0.00000309
argument of perihelion[deg] 306.549632 ± 0.000384
longitude of the ascending node [deg] 334.528730 ± 0.000683
inclination[deg] 9.889591 ± 0.000041
inverse semimajor axis [10-6 au-1] -129.70 ± 3.64

Nongravitational parameters [10-8 au/day2] A1 = 1.002 ± 0.139 A2 = -0.7253 ± 0.0321 A3 = -0.4916 ± 0.0703

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.

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

Epoch (TT) 17110112.0
time of perihelion passage (TT) 20080625.604947 ± 0.000155
perihelion distance 0.85572750 ± 0.00000091
eccentricity 1.00003655 ± 0.00000200
argument of perihelion[deg] 306.192555 ± 0.000064
longitude of the ascending node [deg] 334.735976 ± 0.000045
inclination[deg] 9.764146 ± 0.000017
inverse semimajor axis [10-6 au-1] -42.71 ± 2.34

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 C2007W1R5-001

Comet C/2007 W1 Boattini (non-gravitational solution based on post-perihelion data)

number of observations 777
number of residuals 1522
data interval 2008 June 30 — 2008 Dec. 17
rms [arcsec] 0.59
orbit quality class 2a

Osculating orbital elements (heliocentric; ecliptic J2000.0)

Epoch (TT) 20080623.0 = JD 2454640.5
time of perihelion passage (TT) 20080624.887438 ± 0.000639
perihelion distance 0.84968619 ± 0.00000646
eccentricity 1.00010121 ± 0.00002732
argument of perihelion[deg] 306.554562 ± 0.000676
longitude of the ascending node [deg] 334.523444 ± 0.000279
inclination[deg] 9.888552 ± 0.000515
inverse semimajor axis [10-6 au-1] -119.11 ± 32.15

Nongravitational parameters [10-8 au/day2] A1 = 5.864 ± 0.272 A2 = -0.783 ± 0.172 A3 = 0.136 ± 0.250

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 W1

Figure caption: Six 2D-projections of the 9D space of future swarm (5001 VCs) of C/2007 W1. 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) 23121028.0
time of perihelion passage (TT) 20080624.794149 ± 0.000770
perihelion distance 0.84649114 ± 0.00000555
eccentricity 0.99953072 ± 0.00000601
argument of perihelion[deg] 306.419508 ± 0.000615
longitude of the ascending node [deg] 334.558876 ± 0.000296
inclination[deg] 9.892613 ± 0.000099
inverse semimajor axis [10-6 au-1] 554.38 ± 7.09

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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