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Visible Stars & Constellations

The number of stars in this galaxy is approximately 100,000,000,000. Many stars form or are part of constellations, which are imaginary patterns that look like people, objects or animals from antiquity. The constellations in the zodiac follow the ecliptic, or the same path around the sky as the sun does. Other constellations and their stars are found all over the night sky.

Orion
- Orion is a constellation easily seen in the northern hemisphere during the fall and winter. It's dedicated to a hunter in Greek mythology and has many bright stars. The star in Orion's right shoulder is Betelgeuse, a supergiant star, which may or may not have gone nova. If it has gone nova in the past year the Earth won't know about it for 310 years, as that's how long the light from the explosion will take to reach the Earth. In Orion's left shoulder is the star Bellatrix, a B-type blue-giant star. Bellatrix is about 360 light years from Earth. In Orion's heel is Rigel, a blue, white double star 910 light years from Earth.
Carina
- Carina is named after the keel of the ship Argo. It can be seen in the southern hemisphere. Its brightest star is Canopus, a yellow, white supergiant star that's the second brightest star in the sky, after Sirius, the hound of Orion. As the Carina constellation doesn't have too many bright stars, Canopus was often used for navigation. Canopus has 8.5 times the mass of the sun and its radius is 65 times larger.
Centaurus
- Centaurus was named for Chiron, the centaur who was the mentor of Jason, the leader of the Argonauts. The constellation is part of a very rich star field and contains the stars alpha and beta centauri. Alpha centauri also is known as Rigel Kent and is only 4.34 light years from Earth. It's a multiple star system and the primary star is three times as bright as the secondary. The third star, Proxima, is the closest to Earth. Beta centauri also is known as Hadar.
Taurus
- The Pleiades are named after the daughters of Atlas.
  
  Taurus is a zodiacal constellation named for Jupiter when he was impersonating a bull to abduct the princess Europa. Its brightest star is Aldebaran, and it contains the star clusters the Pleiades and the Hyades. The Hyades outlines the bull's face and are much less numerous and much older than the Pleiades. The Pleiades are about 100 million years old and have about a thousand stars, the Hyades are a few hundred stars that are about a billion years old. Aldebaran is a giant red star that's only about 68 light years from Earth.

Astronomy