Gravity is constantly pulling the matter of a star together, while the nuclear fission reaction that makes the star shine and put off heat is trying to make it explode. The two are very precariously balanced.
Hydrostatic equilibrium is the balance between the inward force of gravity and the outward pressure gradient in a fluid, like in a star or planet. This equilibrium prevents further collapse or expansion by ensuring that the pressure within the fluid supports the weight of the overlying material. In stars, this balance between gravity and pressure helps maintain their stable size and shape.
Pressure and gravity
While the star can produce energy, that keeps the star in balance - it keeps the star from collapsing. By the way, another outward force is the gas pressure, but that, by itself, is not enough to counteract the force of gravity in the case of a star.
The stage that comes first in the life cycle of a high-mass star is the main sequence stage. During this stage, the star fuses hydrogen into helium in its core, maintaining a balance between radiation pressure and gravity.
The balance between pressure caused by heat and gravity caused by the star's mass.
You used the term nebular. I take it you mean a galaxy. There would not be a balance between gravity and pressure. There would be a balance between gravity and centrifugal force.
The balance between gravity and pressure can be upset if two nebulas collide. It can also be upset if a nearby star explodes.
The balance between gravity and pressure can be upset if two nebulas collide. It can also be upset if a nearby star explodes.
Two events that can upset the balance between gravity and pressure in a nebula are a supernova explosion or the collision of two nebulae. A supernova explosion releases an enormous amount of energy and can disrupt the delicate equilibrium between gravity and pressure. The collision of two nebulae can also disturb the balance by introducing additional gravitational forces and increasing the overall pressure within the system.
Nuclear fusion produces heat, and heat creates the pressure which keeps the star from collapsing under its own gravity. The relationship between heat and pressure in a gas is described by the Ideal Gas Laws. It also applies to plasma (which can be described as a super heated gas).
A star maintains equilibrium during the main sequence because the inward force of gravity is balanced by the outward pressure from nuclear fusion in its core. This balance between gravity and radiation pressure prevents the star from collapsing or expanding significantly during this phase.
The sun is held in place by its own gravity, which creates a delicate balance between the outward pressure from nuclear fusion in its core and the inward pull of gravity. This balance keeps the sun stable and prevents it from expanding or collapsing.
The balance between gravity and buoyancy is called equilibrium.
Hydrostatic equilibrium is the balance between the inward force of gravity and the outward pressure gradient in a fluid, like in a star or planet. This equilibrium prevents further collapse or expansion by ensuring that the pressure within the fluid supports the weight of the overlying material. In stars, this balance between gravity and pressure helps maintain their stable size and shape.
Pressure and gravity
Pressure and gravity
The force that keeps a main sequence star from blowing apart is the balance between the outward pressure generated by nuclear fusion in the core and the inward gravitational force pulling matter towards the center. This equilibrium maintains the stability and structure of the star.