RR Lyrae distance estimate of . This type of low-mass star has consumed the hydrogen at its core, evolved away from the main sequence, and passed through the red giant stage. Energy is now being produced by the thermonuclear fusion of helium at its core, and the star has entered an evolutionary stage called the horizontal branch (HB). The effective temperature of an HB star's outer envelope will gradually increase over time. When its resulting stellar classification enters a range known as the instability strip—typically at stellar class A—the outer envelope can begin to pulsate. RR Lyrae shows just such a regular
Red and white giant flying squirrel Red and white giant flying squirrel The red and white giant flying squirrel ("Petaurista alborufus") is a species of rodent in the family Sciuridae. It is the largest species of giant squirrel and has blue eyes. It is also known as the Chinese giant flying squirrel. At over a meter long including its tail, the red and white giant flying squirrel is the largest of its kind. Endemic to central and southern China and Taiwan, they inhabit dense hillside forests in mountainous terrain. They spend their days sleeping, emerging after sundown to forage in the trees. Their diet consists primarily