Comet C/2002 T7 LINEAR

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Dynamics &
Planetology
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C/2002 T7 LINEAR

General description

The Catalogue of Cometary Orbit (Marsden & Williams, 2008, 17^thEd.; MWC08) gives NG orbit based on 3825 observations and significantly shorter arc (2002 Oct. 12 — 2004 June 11). In June 2013, 4517 observations were available at IAU Minor Planet Center Web Pages, that span the same time interval as in the catalogue solution. However, osculating orbit is the same as in MWC08. Since MWC08 gives non-gravitational (NG) orbit, thus orbital quality class is not given there. NG osculating orbit given at JPL Small-Body Database Browser is based on 4399 observations and slightly shorter data interval (2002 Oct. 12 — 2006 March 07).

In Królikowska and Dybczyński (2010) the symmetric NG model based on full data interval is given where some trends in O-C variations are reported. Therefore, two types of orbits are given here (see Królikowska, Dybczyński and Sitarski (2012) for more details):

the nongravitational orbit based on full data interval (SSDP Cometary Note C2002T7N5-001 given just below). This model gives NG orbit of 1a+ class with evident trends in O-C time variations. The asymmetric model gives τ = -12.9 ± 0.6 day, |A₁| <<|A₂|, infinitesimal decrease in rms, and similar evident trends in O-C. Thus, the symmetric model is included here. O-C time variations for this solution are here where magenta points show residuals in right ascension, blue – in declination.
two separate nongravitational osculating orbits based on pre-perihelion (SSDP Cometary Note C2002T7P5-001, see below) and post-perihelion data (SSDP Cometary Note C2002T7R5-001 given below), recommended for studying the past and future dynamical evolution, respectively.
These sets of PRE and POST observations give orbits of 1a and 1b class as well as O-C time variations with no trends in right ascension and declination, see O-C time vatiations for pre-perihelion solution and post-perihelion model.

Figure caption: Time distribution of positional observations with corresponding heliocentric (red points) and geocentric (green points) 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. The same figure in the new window

SSDP Cometary Note C2002T7N5-001

Comet C/2002 T7 LINEAR (non-gravitational solution)

number of observations	4507
number of residuals	8878
data interval	2002 Oct. 12 — 2006 Mar. 20
rms [arcsec]	0.50
orbit quality class	1a+

Osculating orbital elements (heliocentric; ecliptic J2000.0)

Epoch (TT)	20020903.0	= JD 2452520.5
time of perihelion passage (TT)	20040423.145295	± 0.000020
perihelion distance	0.61502190	± 0.00000030
eccentricity	1.00040155	± 0.00000021
argument of perihelion [deg]	157.722612	± 0.000024
longitude of the ascending node [deg]	94.847709	± 0.000011
inclination [deg]	160.571155	± 0.000006
inverse semimajor axis [10^-6 au^-1]	-652.91	± 0.34

Nongravitational parameters [10^-8 au/day²]

A₁ = 0.3822 ± 0.0158

A₂ = 0.30233 ± 0.00416

A₃ = -0.15256 ± 0.00433

Notes: 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)	17060717
time of perihelion passage (TT)	20040423.021385	± 0.000021
perihelion distance	0.61543684	± 0.00000031
eccentricity	0.99998421	± 0.00000020
argument of perihelion [deg]	157.728765	± 0.000024
longitude of the ascending node [deg]	94.834931	± 0.000011
inclination [deg]	160.521009	± 0.000006
inverse semimajor axis [10^-6 au^-1]	25.65	± 0.34

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)	22940316
time of perihelion passage (TT)	20040423.314758	± 0.000017
perihelion distance	0.61391053	± 0.00000040
eccentricity	1.00043817	± 0.00000074
argument of perihelion [deg]	158.241159	± 0.000057
longitude of the ascending node [deg]	95.405415	± 0.000017
inclination [deg]	160.442107	± 0.000008
inverse semimajor axis [10^-6 au^-1]	-713.73	± 1.20

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 C2002T7P5-001

Comet C/2002 T7 LINEAR (non-gravitational solution based on pre-perihelion data)

number of observations	3655
number of residuals	7170
data interval	2002 Oct. 12 — 2004 Apr. 17 (pre-perihelion data)
rms [arcsec]	0.36
orbit quality class	1a

Osculating orbital elements (heliocentric; ecliptic J2000.0)

Epoch (TT)	20020903.0	= JD 2452520.5
time of perihelion passage (TT)	20040423.145323	± 0.000029
perihelion distance	0.61503075	± 0.00000039
eccentricity	1.00040642	± 0.00000030
argument of perihelion [deg]	157.722134	± 0.000033
longitude of the ascending node [deg]	94.847872	± 0.000013
inclination [deg]	160.571223	± 0.000007
inverse semimajor axis [10^-6 au^-1]	-660.81	± 0.49

Nongravitational parameters [10^-8 au/day²]

A₁ = 5.582 ± 0.583

A₂ = 1.632 ± 0.498

A₃ = 0.679 ± 0.154

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)	17060826
time of perihelion passage (TT)	20040423.021348	± 0.000020
perihelion distance	0.61544567	± 0.00000038
eccentricity	0.99998907	± 0.00000025
argument of perihelion [deg]	157.728285	± 0.000029
longitude of the ascending node [deg]	94.835092	± 0.000012
inclination [deg]	160.521073	± 0.000006
inverse semimajor axis [10^-6 au^-1]	17.75	± 0.41

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 C2002T7R5-001

Comet C/2002 T7 LINEAR (non-gravitational solution based on post-perihelion data)

number of observations	848
number of residuals	1659
data interval	2004 Apr. 24 — 2006 Mar. 20 (post-perihelion data)
rms [arcsec]	0.49
orbit quality class	1b

Osculating orbital elements (heliocentric; ecliptic J2000.0)

Epoch (TT)	20040425.0	= JD 2453120.5
time of perihelion passage (TT)	20040423.059326	± 0.000109
perihelion distance	0.61458627	± 0.00000045
eccentricity	1.00041363	± 0.00001161
argument of perihelion [deg]	157.729574	± 0.000254
longitude of the ascending node [deg]	94.855782	± 0.000121
inclination [deg]	160.582686	± 0.000053
inverse semimajor axis [10^-6 au^-1]	-673.03	± 18.88

Nongravitational parameters [10^-8 au/day²]

A₁ = 1.414 ± 0.106

A₂ = 0.4371 ± 0.0781

A₃ = -0.4016 ± 0.0292

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 of this comet.

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

Epoch (TT)	22950130
time of perihelion passage (TT)	20040423.313348	± 0.000068
perihelion distance	0.61388642	± 0.00000073
eccentricity	1.00038541	± 0.00000076
argument of perihelion [deg]	158.237013	± 0.000078
longitude of the ascending node [deg]	95.405068	± 0.000045
inclination [deg]	160.441962	± 0.000006
inverse semimajor axis [10^-6 au^-1]	-627.82	± 1.23

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.

General description

SSDP Cometary Note C2002T7N5-001

Comet C/2002 T7 LINEAR (non-gravitational solution)

Osculating orbital elements (heliocentric; ecliptic J2000.0)

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

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

SSDP Cometary Note C2002T7P5-001

Comet C/2002 T7 LINEAR (non-gravitational solution based on pre-perihelion data)

Osculating orbital elements (heliocentric; ecliptic J2000.0)

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

SSDP Cometary Note C2002T7R5-001

Comet C/2002 T7 LINEAR (non-gravitational solution based on post-perihelion data)

Osculating orbital elements (heliocentric; ecliptic J2000.0)

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

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