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 star See Note at dwarf star

Word History and Origins

Origin of red giant¹

First recorded in 1915–20