Red-giant branch Red-giant branch The red-giant branch (RGB), sometimes called the first giant branch, is the portion of the giant branch before helium ignition occurs in the course of stellar evolution. It is a stage that follows the main sequence for low- to intermediate-mass stars. Red-giant-branch stars have an inert helium core surrounded by a shell of hydrogen fusing via the CNO cycle. They are K- and M-class stars much larger and more luminous than main-sequence stars of the same temperature. Red giants were identified early in the 20th century when the use of the Hertzsprung–Russell diagram made it clear that there
Red and white giant flying squirrel found in mountain areas, they nest in hollow trees. They move between the trees of their ecosystem by gliding by use of a patagium, typically over distances of 10–20 meters although glides of up to 400 meters longer have been observed when they happen to be traveling downhill. This species has a wide distribution and a presumed large population, it occurs in many protected areas, and the International Union for Conservation of Nature has rated it as being of "least concern". Red and white giant flying squirrel The red and white giant flying squirrel ("Petaurista alborufus") is a species of