astrophysics

American  

[as-troh-fiz-iks] / ˌæs troʊˈfɪz ɪks /

noun

(used with a singular verb)

1. the branch of astronomy that deals with the physical properties of celestial bodies and with the interaction between matter and radiation in the interior of celestial bodies and in interstellar space.

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astrophysics British  

/ ˌæstrəʊˈfɪzɪks /

noun

1. (functioning as singular) the branch of physics concerned with the physical and chemical properties, origin, and evolution of the celestial bodies

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astrophysics Scientific  

/ ăs′trō-fĭz′ĭks /

1. The branch of astronomy that deals with the physical and chemical processes that occur in stars, galaxies, and interstellar space. Astrophysics deals with the structure and evolution of stars, the properties of interstellar space and its interactions with systems of stars, and with the structure and dynamics of clusters of stars such as galaxies.

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astrophysics Cultural  

1. The branch of astronomy devoted to the study of the physical characteristics and composition of objects in the sky. Typical concerns of astrophysics are how much light the stars give off and the size, mass, and temperature of planets and stars.

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Other Word Forms

• astrophysical adjective
• astrophysicist noun

Etymology

Origin of astrophysics

First recorded in 1885–90; astro- + physics

Example Sentences

"It'll be exciting, you know, in a slightly scary way, when they go behind the moon," Derek Buzasi, a professor of astronomy and astrophysics at the University of Chicago, told AFP.

From Barron's • Apr. 5, 2026

Initially believed to be interference, the signals turned out to be the first evidence of pulsars, rapidly spinning neutron stars that opened a new field of astrophysics.

From Science Daily • Mar. 14, 2026

The work, presented at the international supercomputing conference SC '25, marks a major step forward for astrophysics, high-performance computing, and AI-assisted modeling.

From Science Daily • Nov. 16, 2025

Bowling balls on a good length that move slightly away is hardly cricketing astrophysics.

From BBC • Nov. 10, 2025

He had probably completed biology by now, she guessed, and would be studying higher mathematics, or astrophysics, or biochemistry, one of the subjects that was whispered about, when they were young, as incomprehensibly difficult.

From "Son" by Lois Lowry