Accretion disc

(Last edited: Tuesday, 16 April 2024, 2:30 PM)


Short Definition:

An accretion disk is a structure, which is an amalgamation of gas, plasma or particles around the black hole. It is attracted by the gravitational pull and orbits the black hole while it slowly spirals into it, so it is a phenomenon that describes the way how a big celestial body amasses matter like black holes.

Detailed Definition:

One can not observe black holes or their event horizon, but since black holes have accretion disks, which are a type of structure and accumulations of gas, plasma or particles that were attracted by the huge gravitational pull of black holes. Humans are able to see those accretion disks, because the spinning matter is so fast, which in turn generates heat and emits x-rays and gamma rays. The high amount of angular momentum makes it impossible for the matter to simply fall into the black hole like it would on earth or one would think. Angular momentum decreases despite there being no friction in space, because of turbulence, which is caused by the fact that rotation increases the effect of magnetic fields. Temperatures in the accretion disks tend to vary quite a bit, which is determined by the composition of the accretion disk and its source. Temperatures can go from a few thousand to a few million Kelvin.


Accretion from Latin ad+ crescere-->accrescere--->accretionem

Disk from Latin discus

Sample Sentence(s):

The accretion disk is the natural consequence of how gravitational pull attracts matter and makes it impossible to simply fall into the black hole.


Many people think they saw a picture of a black hole, but in reality they only saw a picture of its accretion disk.



disque d’accrétion




Dysk akrecyjny



Links to Videos/Articles:

GMS: Black Hole Accretion Disk Visualization (

» Dictionary of Space Concepts