We simulate the tidal disruption of an asteroid close to a white dwarf (WD).
The asteroid is modelled as a rubble pile of 8000 equal-size hard sphere particles. The interactions between the particles are gravity and inelastic collisions and the asteroid is assembled by letting its constituent particles fall freely. The asteroid radius is about 12 km with a bulk density of 2 g/cm^3. The WD is a point mass of 0.75 solar masses. The nominal tidal disruption distance is about 0.06 au.
The asteroid's orbit before the disruption is such that the pericentre and apocentre distances are 0.04 and 10 au, respectively. The initial distance between the WD and the asteroid is 0.1 au and system is tracked for 50 days.
Video one shows the tidal disruption of the asteroid in a frame centred on the it. The video title shows the time since the start of the simulation, distance from the centre of mass (COM) of the asteroid to the WD, and the normalised particle collision intensity (that records the number of particle mutual collisions in a time interval). The x- and y-axes show the position of the particle in the orbital plane in km and have the same scale. The colours show the initial distance from a particle to the COM of the asteroid. The arrow points toward the WD.
Video two shows the disruption in a frame centred on the WD. The x- and y-axes show the position of the COM of the asteroid in au whereas the relative position of each composing particle of the asteroid with respect to the COM is shown in another scale, indicated at the lower left corner. The cross marks the position of the WD.
See Li+2021 for details of the simulation.