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

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

Scientists predict that in a few billion years the sun will expand into a red giant star that will swell up and engulf Earth and the other inner planets.

From Science Daily

"We will not run out of iron till the sun turns into a red giant."

From Science Daily