A Modification To The Gaseous Pressure Gradients In Spherical Celestial Bodies: Effects Of The Thermal Motion

The atmospherical pressure gradients of spherical celestial bodies are very important in astrophysics and other related areas. The classical form of the gradient in a gravitation-dominated celestial body: dp dR = − R ρ has been widely adopted for quit a long time. But, in this form, a factor has been neglected: the centrifugal force that due to the thermal motion of gaseous particles in a centripetal force field. The pressure gradient is actually caused by the “effective weight” f ′ g of gaseous particles but not by their real gravity fg. For this reason, a modified form of the pressure gradient is given in this paper. Though the changes are very small in most celestial bodies, they may be not negligible in theories of stars, accretion disks, and so on with a cumulative effect. Subject headings: spherical celestial bodies — pressure gradient : factor — thermal motion