Hydrostatic Equilibrium

Hydrostatic equilibrium is one of the most important fundamental principles in atmospheric physics and astrophysics.

Hydrostatic equilibrium occurs when compression due to gravity is balanced by a pressure gradient which creates a pressure gradient force in the opposite direction.... , the boundary that separates objects from planethood.

Hydrostatic equilibrium : gravity inwards = pressure outwards stability : stellar thermostat Chapter 12: Stellar Evolution ...

Hydrostatic equilibrium: gravity compression is balanced by pressure outward. Greater gravity compresses the gas, making it denser and hotter, so the outward pressure increases.

Hydrostatic equilibrium gives no net flow in the z-direction: at density r. For a thin disk, this approaches -GMz/r³ so the disk thickness will be H ~ r/M.

Hydrostatic equilibrium A planet's defining physical characteristic is that it is large enough for the force of its own gravity to dominate over the electromagnetic forces binding its physical structure, leading to a state of hydrostatic equilibrium.

HYDROSTATIC EQUILIBRIUM Hydrostatic equilibrium is a stable condition in a star in which the fluid matter within the star is at an equilibrium with respect to all forces, including the inward-pulling force of gravity, ...

Hydrostatic Equilibrium: This refers to the balancing of forces in a fluid (fluid=hydro, static=stationary, equilibrium=balance).

Hydrostatic Equilibrium The balance between weight of the material pressing downward on a layer in a star and the pressure in that layer. I ...

hydrostatic equilibrium -- the condition in which pressure and gravitational forces in a star or planet are in balance. Without such balance,bodies will either collapse or expand.

Hydrostatic Equilibrium - The balance between the inward directed gravitational force and the outward directed pressure force within a celestial body ...

Hydrostatic Equilibrium A balance between the gravitational force inward and the gas and radiation forces outward in a star. Hyperbolic Space ...

The identity of g* and g is implied by the assumption of hydrostatic equilibrium.

saturation-adiabatic lapse rate A special case of process lapse rate, defined as the rate of decrease of temperature with height of an air parcel lifted in a saturation-adiabatic process through an atmosphere in hydrostatic equilibrium.

has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, and has cleared the neighbourhood around its orbit ...

First is the hydrostatic balance, also called hydrostatic equilibrium. This determines the structure of the star as the internal pressure gradient balances against the force of gravity.

A "planet" is a celestial body that (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, ...

This hydrostatic equilibrium condition usually also applies to changes of density inside the object, so that the density at a place inside the object will depend only on how far it is from the object's center.

In many ways stars are very simple objects; round spheres of gas in hydrostatic equilibrium, hot and dense at the centre, much cooler at the surface and as the Astronomer Royal Sir Martin Rees says, much simpler than ants! ...

The ice mass started disappearing over 10000 years ago, but the Earth's crust is still not in hydrostatic equilibrium and is still rebounding (the relaxation time is estimated to be about 4000 years).

hydrostatic equilibrium The balance maintained within a star between the explosive pressure of the core caused by heat and the gravitational attraction of the mass of the star itself.

The position on the H-R diagram for stars which have attained hydrostatic equilibrium and have started hydrogen burning in their cores, but which have not yet had time to produce an observable change in their chemical composition (ZAMS).

horizontal branch Region of the H-R diagram where post-main sequence stars again reach hydrostatic equilibrium. At this point, the star is burning helium in its core, and hydrogen in a shell surrounding the core.

Scientifically, stars are defined as self-gravitating spheres of plasma in hydrostatic equilibrium, which generate their own energy through the process of nuclear fusion.

It states, "A 'planet' is defined as a celestial body that (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, ...

Instead, as the hydrogen is used up by fusion, the star loses the balance of hydrostatic equilibrium and simply contracts and heats up due to gravity.

See also: Mass, Solar, Sun, Earth, Planet