red giant
Noun
Meaning
a large, old, luminous star; has a relatively low surface temperature and a diameter large relative to the sun
Source: WordNetSynonyms
Hypernyms
Examples
A planetary nebula, often abbreviated as PN or plural PNe, is a kind of emission nebula consisting of an expanding, glowing shell of ionized gas ejected from old red giant stars late in their lives.
A star of about 0.5 M will be able to reach temperatures high enough to fuse helium, and these "mid-sized" stars go on to further stages of evolution beyond the red giant branch.
At this point it will pass through a red giant stage, then settle down to become a white dwarf.
Beta Gruis is a red giant variable star with a minimum magnitude of 2.3 and a maximum magnitude of 2.0.
As a red giant, the Sun will lose roughly 30% of its mass, so, without tidal effects, Earth will move to an orbit convert from the Sun when it reaches its maximum radius.
Either of these changes cause the hydrogen shell to increase in temperature and the luminosity of the star to increase, at which point the star expands onto the red giant branch.