Centaurus the Centaur is a constellation found in the Southern Hemisphere. It is a south circumpolar constellation, which means that it circles close to the south celestial pole and is visible to people in the Southern Hemisphere all year.
Stars of Centaurus
The two most important stars of Centaurus are only four and a half degrees apart. These two bright stars are Alpha Centauri, also known as Rigel Kentaurus, and Beta Centauri, also known as Hadar.
Alpha Centauri, Beta Centauri, Proxima Centauri
Alpha Centauri is the third brightest star in the sky. Its brightness is due to the fact that it is the closest star to Earth. Alpha Centauri shines at magnitude -0.27 from a distance of 4.3 light-years. Alpha Centauri is actually a three-star system. Alpha Centauri A and B are both sunlike stars, with A outshining B. The third star is a faint red dwarf. This star, Alpha Centauri C, is also known as Proxima Centauri because out of the three in the system, it is the closest to Earth. By itself, it shines at 11th magnitude.
Beta Centauri, or Hadar, is magnitude 0.61 and lies 525 light-years away. This blue-white supergiant is sometimes considered the 10th brightest star in the sky (this ranking is occasionally taken by Betelgeuse in Orion). Beta, when compared to its bright neigbhbor Alpha, looks distinctly bluer.
One other notable named star in Centaurus is Menkent, or Theta Centauri. It lies 24 degrees north of Alpha and Beta. Theta is magnitude 2.06 and lies 61 light-years away.
Deep-Sky Objects in Centaurus: Omega Centauri, The Running Chicken, and a Blue Planetary
Omega Centauri (NGC 5139) is the best-known deep-sky object in the constellation of the Centaur. Omega Centauri is a magnificent globular cluster that can be found about halfway between Beta and Theta Centauri and a few degrees to the west. At magnitude 3.7, the cluster can be seen without optical aid, and even binoculars or a small telescope bring out its wonders. This crowded cluster is an old collection of stars in our galaxy about 18,300 light-years away. The globular cluster is about 12 billion years old.
The Running Chicken is the name given to IC 2944. It is found on the other side of Crux from Alpha and Beta Centauri, where Centaurus wraps around the Southern Cross. At the southern tip of Centaurus is this star cluster with nebulosity shining at magnitude 4. The star Lambda Centauri is found here along with dark clouds that stick out in front of the background nebulosity. These dark clouds are known as Bok globules.
The last-deep sky target is NGC 3918, known as the Blue Planetary. This planetary nebula shines at magnitude 8 and lies about 6 degrees north of the Running Chicken. It bears a resemblance to Neptune through a telescope.
