Roche lobe

The Roche lobe is the region around a star in a binary system within which orbiting material is gravitationally bound to that star. It is an approximately tear-drop-shaped region bounded by a critical gravitational equipotential, with the apex of the tear drop pointing towards the other star (the apex is at the L₁ Lagrangian point of the system).

The Roche lobe is different from the Roche sphere which approximates the gravitational sphere of influence of one astronomical body in the face of perturbations from another heavier body around which it orbits. It is different from the Roche limit which is the distance at which an object held together only by gravity begins to break up due to tidal forces. The Roche lobe, Roche limit and Roche sphere are named after the French astronomer Édouard Roche.

Definition

In a binary system with a circular orbit, it is often useful to describe the system in a coordinate system that rotates along with the objects. In this non-inertial frame, one must consider centrifugal force in addition to gravity. The two together can be described by a potential, so that, for example, the stellar surfaces lie along equipotential surfaces.

This page contains text from Wikipedia, the Free Encyclopedia - https://wn.com/Roche_lobe

Latest News for: roche lobe

Edit

CXOGBS J175553.2-281633 is a cataclysmic variable, study finds

Phys Dot Org 29 Sep 2020

An international team of astronomers has performed photometric observations of a binary system known as CXOGBS J175553.2-281633 ... This would bring the accretion rate to M ∼ 1017 g s−1, closer to the M expected for a Roche Lobe ﬁlling subgiant with an orbital period of 10 hours," the researchers explained. Explore further ... More information ... .......

Edit

The first ultra-hot Neptune, LTT 9779b, is one of nature's improbable planets

Phys Dot Org 22 Sep 2020

But if the star is so old, why does any atmosphere exist at all? Well, if LTT 9779b started life as a gas giant, then a process called Roche Lobe Overflow could have transferred significant amounts of the atmospheric gas onto the star.". Roche Lobe Overflow is a process whereby a ......

Edit

Asteroid Bennu Might Spin Itself To Death

IFL Science 20 Mar 2019

And that’s how the researchers discovered that the ground at its equator is outside its Roche lobe ... “As that Roche lobe narrows further and further around the equator, it becomes easier and easier for this asteroid to lose material,” lead author of one of the papers, Daniel Scheeres from the University of Colorado Boulder, said in a statement....