planetary nebula

noun

: a usually compact luminous ring-shaped nebula that is composed of matter which has been ejected from a hot star at its center

Examples of planetary nebula in a Sentence

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This image features a deep field view of the Cassiopeia constellation immersed in the glow of ionized hydrogen gas, where the two small planetary nebulas can be found, Abell 6 and the larger HFG1. Miguel Claro, Space.com, 22 Mar. 2025 This planetary nebula is the remains of a star similar to the sun, which shed most of its mass at the end of its life, with its core becoming a smoldering white dwarf shrouded by this ex-stellar material. Robert Lea, Space.com, 5 Mar. 2025 Despite their name, planetary nebulas are not related to planets. Carlyn Kranking, Smithsonian Magazine, 23 July 2024 Another class of object that the dusty blobs could hypothetically be—but are not—is a compact planetary nebula or CPN. Elizabeth Rayne, Ars Technica, 4 July 2024 See All Example Sentences for planetary nebula

Word History

First Known Use

1785, in the meaning defined above

Time Traveler
The first known use of planetary nebula was in 1785

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Cite this Entry

“Planetary nebula.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/planetary%20nebula. Accessed 4 Apr. 2025.

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