Arcturus is a red giant star in the Northern Hemisphere of Earth's sky and the brightest star in the constellation Boötes (the herdsman). Arcturus is among the brightest stars that can be seen from Earth. Astronomers say Arcturus will end up as a white dwarf at the end of its life.
The name Artcurus comes from the Greek meaning "keeper or guardian of the bear", which refers to the its position adjacent to the tail of the constellation Ursa Major (the Great Bear). It is about 37 light years from earth.
Arcturus, has a lower temperature than the sun, which means that a lot of the red giant star's energy is radiated as heat. Once this is accounted for, Arcturus actually releases 215 times more heat than Earth's sun. Arcturus has an apparent magnitude of -0.04 and an absolute magnitude of 0.2. (The brighter the star, the lower its apparent and absolute magnitudes.) The star is in the latter stages of its life. Considered a red giant, Arcturus has stopped fusing hydrogen in its core, as the sun does, and astronomers believe it is now starting to fuse heavier elements such as carbon
Once Arcturus exhausts its helium supply, its outer layers will likely bleed off, leaving behind a white dwarf remnant and turn into a planetary nebula similar to Abel 31.
