Ursa Minor: Difference between revisions

Ursa Minor (Latin: "Smaller She-Bear", contrasting with Ursa Major), also known as the Little Bear, is a constellation in the northern sky. Like the Great Bear, the tail of the Little Bear may also be seen as the handle of a ladle, hence the name Little Dipper. It was one of the 48 constellations listed by the 2nd century astronomer Ptolemy, and remains one of the 88 modern constellations. Ursa Minor is notable as the location of the north celestial pole, although this will change after some centuries due to the precession of the equinoxes.

Polaris, the brightest star in the constellation, is a yellow-white supergiant and brightest Cepheid variable star in the night sky, ranging from apparent magnitude 1.97 to 2.00. Beta Ursae Minoris, also known as Kochab, is only slightly fainter, with its apparent magnitude of 2.08. An ageing star that has swollen and cooled to become an orange giant, it has a been found to have a planet orbiting it in 2014. It and magnitude 3 Gamma Ursae Minoris have been called the 'guardians of the pole star'. Three other stellar systems have been discovered to contain planets.<ref>[http://en.wikipedia.org/wiki/Ursa_Minor Ursa Minor]</ref>