Red Giant
A late evolutionary stage of a medium-mass star where the outer layers expand and cool after hydrogen fusion in the core ceases. Red giants can eventually shed their outer envelopes, forming planetary nebulae.
Source: esa.int
APODs including "Red Giant"
Moon Lightning
07/10/2004
Moonsets are not often quite as exciting as this one. But amateur astronomer Marc-Andre Besel was impressed by the brilliant lighting displays that joined the first quarter Moon and stars of the constellation Scorpius in western skies. On August 22, 2004, his view looked across the Gulf of Mexico from Anna Maria Island, Florida, USA, a region that would experience even more stormy weather in the coming days. The alluring digital image is a time exposure, by chance capturing the details of a brief flash of lightning along with an overexposed Moon and dramatic cloud formations. In fact, the exposure is long enough to show the background stars as short streaks or trails. The bright yellowish star trail, just above and right of the lightning flash, is red giant star Antares.