2002 TD60 - modelling

For lightcurve data and preliminary analysis, see here.

Petr Scheirich, 2003 November 16.

The modelling of lightcurve by triaxial ellipsoid in complex rotation state revealed two undistinguishable solutions, prograde and retrograde, with almost exactly same synthetic lightcurve.

Comparison of the lightcurve and model data:


2002 / 11 / 07, phase = 27 deg.


2002 / 11 / 08, phase = 26 deg.


2002 / 11 / 11, phase = 22.6 deg.


2002 / 11 / 13, phase = 19.8 deg.


2002 / 11 / 14, phase = 18.5 deg.


2002 / 11 / 24, phase = 4.5 deg.


2002 / 12 / 02, phase = 8.0 deg.


2002 / 12 / 03, phase = 9.6 deg.


2002 / 12 / 07-08, phase = 15.0-15.9 deg.


2002 / 12 / 09, phase = 17.0 deg.


2002 / 12 / 12, phase = 20.4 deg.

Sample of rotating asteroid as seen from Earth:


L is the angular momentum vector

Simulations of Ellen Howell's radar data from Arecibo:

2002-11-20 04:33 UT

Position at synthetic lightcurve:

Movement of asteroid and radial velocities of surface points:
(Color images represent schematic "dopplerogram" - red points are moving away from observer and blue ones towards him).

Prograde solutionRetrograde solution


2002-11-21 04:30 UT

Position at synthetic lightcurve:

Movement of asteroid and radial velocities of surface points:
Prograde solutionRetrograde solution


2002-11-22 04:14 UT

Position at synthetic lightcurve:

Movement of asteroid and radial velocities of surface points:
Prograde solutionRetrograde solution


2002-11-23 04:15 UT

Position at synthetic lightcurve:

Movement of asteroid and radial velocities of surface points:
Prograde solutionRetrograde solution

Monolith possibility

To assess the possibility of monolithic structure I examined the total acceleration (gravitational + centrifugal) at the surface of the body. It reveals probable monolithical structure for mean density bellow ~ 3.2 - 3.5 g/cm3 limit. This charts show evolution of the lowest acceleration at the surface for various densities. Negative value means the acceleration vector heads outwards of the body. (Note that scale for acceleration is reverse.)
The lengths of ellipsoid axes are fixed at values: a=97.8 m; b=55.0 m; c=152.8 m.
Lightcurves are added for comparison.

Density = 2 g/cm3:


Graphical demonstration (positive values of acceleration with blue color, negative in red):

Density = 3 g/cm3:


Graphical demonstration (positive values of acceleration with blue color, negative in red):

Density = 3.2 g/cm3:


Graphical demonstration (positive values of acceleration with blue color, negative in red):

Density = 3.5 g/cm3:


Graphical demonstration (positive values of acceleration with blue color, negative in red):