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

Teams of astronomers were able to detect that circumstellar material for 2023ixf as the supernova expanded outward and crashed into it, producing a discernible shockwave.

From Scientific American • Jul. 21, 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

Each image shows an embedded circumstellar disk orbiting a very young star.

From Textbooks • Oct. 13, 2016