accretion disk

American  

noun

Astronomy.

1. the rapidly spinning disk of gas that forms around the more compact component of a close binary star system as mass is transferred to the compact companion from the primary star.

---

accretion disk Scientific  

1. A spinning disk of gas and dust surrounding a celestial object with an intense gravitational field, such as a star or a black hole. In binary star systems, the gravitational attraction of the denser star can pull matter from the other star into an accretion disk in its own orbit. The material in the accretion disk eventually spirals into the attracting star and adds to its mass. The gas in accretion disks that surround black holes becomes condensed and heated as it is sucked into the hole, emitting x-rays and other radiation that provide evidence for the presence of the black hole.

---

Etymology

Origin of accretion disk

First recorded in 1975–80

Example Sentences

See Examples For:

accretion disk

"With XRISM, we have the greatest resolution observing the brightest AGN and we're getting the richest information on outflows that we have observed so far for an accretion disk," Xiang said.

From Science Daily ● Jun. 19, 2026

This points to changes in how the accretion disk and corona interact over roughly the last 6.5 billions of years.

From Science Daily ● Dec. 27, 2025

Active galactic nuclei occur when material spirals into a galaxy's central black hole, forming an extremely hot accretion disk.

From Science Daily ● Nov. 29, 2025

Most of the emitted light, for example visible light and X-ray, get blocked by thick layers of cosmic dust and can’t pass through the accretion disk around them.

From Space Scoop ● Mar. 27, 2025

Eventually the entire accretion disk is torn in half, with the black hole first consuming the inner disc and then the outer one.

From Salon ● Sep. 18, 2024