Guide to Explore the Constellation Centaurus

Space, Science
Guide to Explore the Constellation Centaurus
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Centaurus Constellation in General

One of the largest constellations of the southern sky is Centaurus. The constellation is the home of the nearest star to our solar system, Proxima Centauri and represents Chiron the Centaur, a mythical half-man, half-horse creature of the Greek mythology that was accidentally killed by Hercules.

Main Characteristics of the Centaurus Constellation

  • Abbreviation: Cen
  • Symbolism: the Centaur
  • Right ascension: 13 h
  • Declination: −50°
  • Area: 1060 sq. deg. (The 9th largest constellation by area.)
  • Main stars: 11
  • Brightest star: α1 Cen (−0.01m)
  • Nearest star: Proxima Centauri (α Cen C)
  • Distance of the nearest star: 4.24 ly, 1.30 pc
  • No messier objects

Bordering constellations

Centaurus and Bordering Constellations

  • Antlia
  • Carina
  • Circinus
  • Crux
  • Hydra
  • Libra
  • Lupus
  • Musca
  • Vela

The central constellation of the image is Centaurus.

Brightest Stars of Centaurus

Relative sizes from left to right the Sun, α Centauri A, α Centauri B and Proxima Centauri

Rigil Kentaurus or Alpha Centauri is part of a triple star system that consists of Alpha Centauri A and B, a binary star and Proxima Centauri (foot of the Centaur). Proxima Centauri is a red dwarf at a distance of 4.37 light-years and it is thought to be the closest star to the Sun.

Depiction of Proxima Centari

Agena or beta Centauri (knee of the Centaur) is a magnitude 1 blue-white giant at a distance of 525 light-years.

Hadar (ground of the Centaur) is a triple star, the 11th brightest star of the sky. Both Hadar and Alpha Centauri are called the Southern Pointer Stars since they point to the Southern Cross.

Menkent or theta Centauri (shoulder of the Centaur) is a 2.06 magnitude orange giant and it is the third brightest star of the constellation. Menkent’s distance from Earth is 61 light-.years.

Lucy or BPM 37093 is a white dwarf made of carbon atoms at a distance of 50 light-years. It is the “largest known diamond” equal to 10 billion trillion trillion carats!

Deep Sky Objects and Meteor Showers of Centaurus

DEEP SKY OBJECTS:

  • Globular cluster Omega Centauri (NGC 5139)
  • Radio source Centaurus A (lenticular galaxy NGC 5128)
  • Galaxy ESO 325-G004

METEOR SHOWERS:

  • Alpha Centaurids: Visible in early February (maximum about three meteors an hour).
  • Omicron Centaurids: Visible from late January through February. The peak is in mid-February
  • Theta Centaurids: Visible from late January to middle March. This is a weak meteor shower.

Mythology and History of the Constellation

A few thousand years ago, Centaurus was an equatorial constellation. However the precession of the Earth’s axis, has moved it to the southern sky. Since this is a periodic phenomenon, the constellation will become visible again by both hemispheres after thousands of years. The first to mention the constellation were Eudoxus and Aratus, during the 4th and the 3rd century BCE respectively. Ptolemy was the first to catalog 37 of the constellation’s stars in the 2nd century AD.

As far as mythology is concerned, centaurs were mythical creatures half-men, half-horse that lived in the region of Magnesia and Mount Pelion in Thessaly, Greece. Chiron was the wise king of the centaurs.

During a fight between Hercules and the centaurs, a poisoned arrow accidentally strikes Chiron on the knee. Chiron was immortal and the wound could only cause him eternal pain. In order for Chiron not to suffer any more, Zeus and Prometheus agree to take away his immortality and place him among the stars. The outline of Centaurus in the night sky actually resembles a centaur.

How to Find Centaurus in the Southern Sky

Some of the brightest stars in the southern sky belong to the asterisms of Centaurus and the Southern Cross. Centaurus is a clearly discernible constellation that wraps around the Southern Cross. As soon as you locate the two brightest stars Alpha and Beta Centauri, you will be able to see the rest of the constellation. It resembles a centaur facing toward Lupus the Wolf, holding a sword or a spear. The Southern Cross lies just under the belly of the centaur. With the use of a small telescope or binoculars, it is easy to distinguish the three stars of the Alpha Centauri triple system.

From these constellations, it is possible to locate other fainter constellations in the southern sky.

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