The Great Bear
Ursa Major
Brightest star: Alioth
Overview
Ursa Major is the third-largest constellation in the sky, covering about 1,280 square degrees. It is most famous for containing the Big Dipper (known as the Plough in Britain), a seven-star asterism that is probably the most recognized star pattern in the Northern Hemisphere. Its brightest star, Alioth (Epsilon Ursae Majoris), shines at magnitude 1.8. Five of the seven Dipper stars share a common motion through space, forming the core of the Ursa Major Moving Group, one of the nearest star clusters to Earth. The two pointer stars, Dubhe and Merak, point directly toward Polaris. Ursa Major is circumpolar from most northern latitudes and visible year-round.
Mythology
Ursa Major has been seen as a bear by cultures across the Northern Hemisphere, from Greece to Native America, suggesting an origin deep in human prehistory. In Greek mythology, the nymph Callisto was transformed into a bear by the jealous goddess Hera (or in some versions by Artemis or Zeus). Her son Arcas, not recognizing her, nearly killed her while hunting. Zeus intervened by placing both in the sky as Ursa Major and Ursa Minor. Hera, still angry, asked Oceanus never to let the bears bathe in the sea, which is why circumpolar constellations never set below the horizon. In Hindu tradition, the seven Dipper stars are the Saptarishi, the seven great sages.
Astrological Significance
While not a zodiac constellation, Ursa Major has been one of the most astrologically significant star groups throughout history. The Big Dipper has served as a celestial clock, calendar, and compass for millennia. In Chinese astrology, the seven stars of the Dipper are the celestial palace of the supreme deity and determine the fate of nations. In Vedic astrology, the Saptarishi (seven sages) represent divine wisdom channeled through the stars. The pointer function connecting to Polaris links Ursa Major to themes of guidance, direction, and finding one's true path. The Great Bear also represents protective maternal energy and the fierce guardianship of those we love.
Observing Tips
Ursa Major is visible year-round from most of the Northern Hemisphere. The Big Dipper is the starting point for finding many other celestial landmarks. Follow the pointer stars Dubhe and Merak northward to Polaris. Follow the arc of the Dipper's handle to the bright star Arcturus in Bootes, and onward to Spica in Virgo. Mizar and Alcor in the Dipper's handle form a famous naked-eye double, and Mizar itself splits into a telescopic double. The constellation contains several fine galaxies, including M81 and M82 (Bode's Galaxy and the Cigar Galaxy), a stunning pair visible in the same telescopic field. The Pinwheel Galaxy (M101) and the Owl Nebula (M97) are other highlights.