accretion disk

noun

variants or less commonly accretion disc

plural accretion disks also accretion discs

: a disk of usually gaseous matter surrounding a massive celestial object (such as a black hole) in which the matter gradually spirals in toward and accretes onto the object as a result of gravitational attraction

Evans' team studied a supermassive black hole with jets 800 million light-years away named 3C 33. They never found an expected X-ray pattern … which results from light reflecting off the accretion disk.

—Bill Andrews

Most other moons are either captured planetesimals, or they formed along with the planet in a common accretion disc.

—Daniel Herwartz, et al.

Examples of accretion disk in a Sentence

Recent Examples on the Web

This maximum is due to the amount of torque on the black hole generated by radiation emitted from the accretion disk and swallowed by the black hole. —Isaac Schultz / Gizmodo, Quartz, 23 May 2024

Cloud structures called photon rings and a flat, swirling cloud of hot, glowing gas called an accretion disk surrounding the black hole serve as a visual reference during the fall. —Eric Lagatta, USA TODAY, 7 May 2024

Occasionally, bits of the accretion disk fall into the black hole, causing visible flare-ups that astronomers can observe and document. —Isaac Schultz / Gizmodo, Quartz, 7 May 2024

This luminosity is due to the heating of matter and gas that surround black holes and make up their accretion disks, resulting in the emission of light across various wavelengths. —Isaac Schultz / Gizmodo, Quartz, 27 Mar. 2024

Word History

First Known Use

1972, in the meaning defined above