Solar System
Dynamics &
Planetology
Group 		C/2003 WT42 LINEAR



data set of C/2003 WT<sub>42</sub>

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General description

Comet C/2003 WT42 was discovered on 19 November 2003 by LINEAR as an apparently asteroidal object; observations raported in mid-January 2004 [IAUC 8270, 2004 January 16] demostrated the cometary appearance. Three images of this object were found on LINEAR exposures taken on 30 October 2003. Comet passed perihelion in April 2006 (see below).

C/2003 WT42 was observed 4.6 yr during five oppositions in a range of heliocentric distances: 8.26 au – 5.191 au (perihelion) – 7.66 au.

Comet had its closest approach to Earth on 3 February 2006 (4.403 au, about two months before perihelion).

Balistic solution given below reveals some trends in (O-C) where most prominent are in the last opposition (see lower panel in the figure). It seems that there are any NG effects detectable on the basis of positional data.

Older solution based on the same data set but on different approach to data weighting is available here, where trends in (0-C) are more noticeable than in this solution.

Nakano solution [ Nakano Notes 1636] also gives trends in (O-C) in the last opposition, however many of observations taken in this opposition are discarded, for example all data (14 measurements) after 2008 March 31. His solution is based on 2382 observations (arc: 2003 October 30 to 2008 March 31; rms = 0.60 arcsec) and gives 1/aorigin = +0.000029, 1/afuture = +0.000183).

Solution based on first three oppositions also gives very similar original 1/a to this obtained on the basis of the complete data set (1/aorigin = +0.00047; see second solution given below).



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 line shows the perihelion distance for a given comet whereas vertical dotted line — the moment of perihelion passage. Lower panel: O-C diagram for the gravitational solution shows some trends in right ascension (magenta dots) and declination (blue open circles), mainly in the last apparition.




SSDP Cometary Note C2000WTA5-001

Comet C/2003 WT42 LINEAR

number of observations 2564
number of residuals 5071
data interval 2003 Oct. 30 — 2008 May 25
rms [arcsec] 0.46
orbit quality class 1a+

Osculating orbital elements (heliocentric; ecliptic J2000.0)

Epoch (TT) 20060415.0 = JD 2453840.5
time of perihelion passage (TT) 20060410.767044 ± 0.000157
perihelion distance 5.19092150 ± 0.00000101
eccentricity 1.00256151 ± 0.00000135
argument of perihelion [deg] 92.467272 ± 0.000018
longitude of the ascending node [deg] 48.453876 ± 0.000007
inclination [deg] 31.410659 ± 0.000003
inverse semimajor axis [10-6 au-1] -493.46 ± 0.26

Note: Epoch is given in a format: yyyymmdd.d, time of perihelion passage in a format of yyyymmdd.dddddd.
data set of C/2003 WT<sub>42</sub>

Figure caption: Six 2D-projections of the 6D space of original swarm (5001 VCs) of C/2003 WT42. 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) 17000419
time of perihelion passage (TT) 20060411.899846 ± 0.000159
perihelion distance 5.18221697 ± 0.00000113
eccentricity 0.99975762 ± 0.00000136
argument of perihelion [deg] 92.605011 ± 0.000018
longitude of the ascending node [deg] 48.434892 ± 0.000007
inclination [deg] 31.434394 ± 0.000003
inverse semimajor axis [10-6 au-1] 46.77 ± 0.26

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/2003 WT<sub>42</sub>

Figure caption: Six 2D-projections of the 6D space of future swarm (5001 VCs) of C/2003 WT42. 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) 23140220
time of perihelion passage (TT) 20060410.407702 ± 0.000158
perihelion distance 5.18237935 ± 0.00000108
eccentricity 0.99895846 ± 0.00000135
argument of perihelion [deg] 92.354993 ± 0.000018
longitude of the ascending node [deg] 48.405146 ± 0.000007
inclination [deg] 31.423892 ± 0.000003
inverse semimajor axis [10-6 au-1] 200.98 ± 0.26


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.





SSDP Cometary Note C2000WTP5-001 – solution based on first three oppositions

Comet C/2003 WT42 LINEAR

number of observations 1692
number of residuals 3339
data interval 2003 Oct. 30 — 2006 Aug. 04
rms [arcsec] 0.39
orbit quality class 1a+

Osculating orbital elements (heliocentric; ecliptic J2000.0)

Epoch (TT) 20060415.0 = JD 2453840.5
time of perihelion passage (TT) 20060410.765562 ± 0.000408
perihelion distance 5.19093047 ± 0.00000277
eccentricity 1.00256017 ± 0.00000181
argument of perihelion [deg] 92.466984 ± 0.000053
longitude of the ascending node [deg] 48.453974 ± 0.000009
inclination [deg] 31.410697 ± 0.000004
inverse semimajor axis [10-6 au-1] -493.20 ± 0.35

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) 17000419
time of perihelion passage (TT) 20060411.898367 ± 0.000406
perihelion distance 5.18222591 ± 0.00000272
eccentricity 0.99975629 ± 0.00000180
argument of perihelion [deg] 92.604724 ± 0.000053
longitude of the ascending node [deg] 48.434990 ± 0.000009
inclination [deg] 31.434433 ± 0.000004
inverse semimajor axis [10-6 au-1] 47.03 ± 0.35

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.





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