red giant

noun

, Astronomy.

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

red giant

noun

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

red giant

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 starSee Note at dwarf star

Word History and Origins

Origin of red giant¹

First recorded in 1915–20

Example Sentences

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

The phenomenon occurs when a white dwarf and red giant star orbit each other.

From Los Angeles Times

Astronomers have discovered a new type of red giant star near the centre of the galaxy.

From BBC

Analysis of the spectra for seven of these stars, compared with data from earlier surveys, concluded that they were in fact a new type of red giant star.

From Science Daily