Selfgravitation

Self-gravitation refers to the gravitational attraction of an object on itself. It is a fundamental force that arises from the mass of the object itself. When an object possesses sufficient mass, its own gravity can overcome other forces and cause it to collapse or hold together. This phenomenon is crucial in the formation and evolution of astronomical bodies.

For example, in the formation of stars and planets, vast clouds of gas and dust begin to coalesce due to self-gravitation. As the material clumps together, its density increases, and the gravitational pull becomes stronger. This process continues, leading to the formation of denser cores that can eventually ignite nuclear fusion (in stars) or accrete more material to form planets. The stability of stars and planets is also largely maintained by self-gravitation, which counteracts outward pressures.

The concept of self-gravitation is also relevant in understanding the behavior of fluids and gases under their own gravity. For instance, in astrophysics, the Jeans instability describes the condition under which a cloud of gas will collapse due to self-gravitation, leading to star formation. The strength of self-gravitation depends directly on the mass and inversely on the square of the distance between the mass elements within the object. Objects with very low mass, like small asteroids, exhibit negligible self-gravitation, and their shape is primarily determined by the composition and internal material strength.