red giant

American  

noun

Astronomy.

1. a star in an intermediate stage of evolution, characterized by a large volume, low surface temperature, and reddish hue.

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red giant British  

noun

1. a giant star towards the end of its life, with a relatively low temperature of 2000–4000 K, that emits red light

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red giant Scientific  

1. A giant star that has a relatively low surface temperature, giving it a reddish or orange hue. Red giants are non-main-sequence stars positioned in the upper right of the Hertzsprung-Russell diagram. They are not massive stars but rather late, expanded stages of lower-mass main-sequence stars that have exhausted the hydrogen in their core and are fusing their remaining hydrogen into helium in a luminous outer shell. The Sun is expected to become a red giant in about 5 billion years, expanding to 70 times its current size and bringing its surface extremely close to Earth's present orbit.

2. See more at star See Note at dwarf star

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Etymology

Origin of red giant

First recorded in 1915–20

Example Sentences

That is the conclusion of a new study from Chalmers University of Technology in Sweden, based on close observations of the red giant star R Doradus.

From Science Daily

These observations show the star completes one full rotation every 398 days, which is unusually fast for a red giant of its age that evolved alone.

From Science Daily

When stars like the Sun exhaust their hydrogen fuel, they begin to cool and expand, transforming into red giants.

From Science Daily

A small white dwarf, which is a dead star, is locked in a cosmic dance with a much larger red giant - a star that's reaching the end of its life.

From BBC

The distance ladder method involves measuring objects, like bright stars called Cepheids or stars at the tip of the red giant branch, and comparing them to objects further away to determine the rate of expansion.

From Salon