spiral arm

noun

Astronomy.

1. any of the elongated and curved spiral sections that are connected to the center of a spiral galaxy.

Word History and Origins

Origin of spiral arm¹

First recorded in 1910–15

Example Sentences

A few years ago, astronomers uncovered one of the Milky Way’s greatest secrets: an enormous, wave-shaped chain of gaseous clouds in our sun’s backyard, giving birth to clusters of stars along the spiral arm of the galaxy we call home.

Read more on Science Daily

Since the Radcliffe Wave appears to form the backbone of the nearest spiral arm in the Milky Way, the waving of the wave could imply that spiral arms of galaxies oscillate in general, making galaxies even more dynamic than previously thought.

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It also could hold clues to why the Milky Way has its spiral arm.

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This discovery also connects spiral arm instabilities to the episodic growth bursts - a key factor for how high-mass stars form.

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The court heard Harvey had sustained other injuries in the weeks prior to his death including a spiral arm fracture, a scrape on his back and marks on his ears and face.

Read more on BBC