The interaction between the materials generated during the disruption process and the central object can generate various explosive phenomena in X-ray, optical, and even radio bands, depending on the system parameters and chemical composition of the disrupted object.

At present, studying the dynamic evolution of clumps partially disrupted from a planet is a research gap, and related research is of great significance for deepening the understanding of the origin and mechanism of repeated burst phenomena.

Recently, Dr. Abdusattar Kurban from the Xinjiang Astronomical Observatory of the Chinese Academy of Sciences, along with his collaborators, investigated the dynamic evolution of the clumps partially disrupted from a planet around a neutron star.

The research results have been published in the international journal Monthly Notices of the Royal Astrological Society (MNRAS, 2023, 522, 4265-4274)

Tidal disruption could occur in any system if system parameters satisfy the tidal disruption condition. Partial or complete disruption may occur depending on the distance between the central object and the planet. When a rocky planet is partially disrupted in an elliptical orbit, it loses a small portion of its mass, and the remaining portion moves in an orbit similar to its original orbit. The clumps generated during the disruption process move in different elliptical orbits.

The clumps, the remnant planet, and the neutron star form a multi-body system. When the interaction between clumps is ignored, a clump, the surviving part of the planet, and the neutron star can be considered as a simple three-body system. In such a system, the gravitational perturbation of the remnant planet is an undeniable factor that dominates the process of the clump's evolution.

This figure presents the period (Pclorb) and angular momentum evolution time scale (tevo) of the clump as a function of planetary mass. Panel (a) and (b) show the cases of Fe planets and MgSiO3 planets, respectively. It can be seen from the figure that the time scale of the angular momentum evolution for a clump is comparable to the orbital period of the clump itself.

The researchers found that under the gravitational perturbation of the surviving part of the planet, clumps lose their angular momentum in a short period of time and finally fall onto the surface of the neutron star, causing collisions. The structural and orbital parameters of the planet are key parameters that affect the processes such as tidal disruption and evolution of the clumps.