circumstellar

American  

[sur-kuhm-stel-er] / ˌsɜr kəmˈstɛl ər /

adjective

1. surrounding a star.

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Etymology

Origin of circumstellar

First recorded in 1950–55; circum- + stellar

Explanation

Things, conditions, or phenomena that are circumstellar revolve around or exist in the region around a star. For example, some stars have circumstellar disks of gas, dust, and debris orbiting them. In addition to circumstellar disks, there are circumstellar winds — streams of particles that flow outward from a star. Astronomers also talk about "circumstellar habitable zones," where conditions around a star can support life as we know it. The star at the center of our solar system is the Sun; of the planets orbiting the Sun, only Earth is in its circumstellar habitable zone, while Venus and Mars are on the edges of it. Circumstellar is built from circum-, "around," and stellar, "of the stars."

Example Sentences

This source became known as Fomalhaut cs1, short for circumstellar source 1.

From Science Daily • Jan. 7, 2026

This marks where the supernova blast wave is ramming into surrounding circumstellar material.

From Science Daily • Dec. 12, 2023

The technique is especially sensitive to planets orbiting far from their stars—a circumstellar region that remains scarcely probed by other planet-hunting methods.

From Scientific American • Oct. 5, 2023

Since V883 Orionis' circumstellar disk is hot enough that the water in it has turned into gas, astronomers saw an opportunity to study it to help understand the evolution of water in solar systems.

From Salon • Mar. 15, 2023

The star is embedded in a shroud of dust and gas that obscures our visible-light view of a circumstellar disk around the star.

From Textbooks • Oct. 13, 2016