Columba (the Dove) is situated in the southern part of the celestial hemisphere, and was created by Dutch astronomer Petrus Plancius in 1592, although a derivation of the constellation may have been known about for millenia. Its brightest star, Phact, is a blue-white subgiant of 2.60 magnitude located 270 light years from our solar system.
Location
Columba is the 54th largest constellation in the night sky, and can be seen by observers located between +45° and -90° of latitude, although best seen in February by northern hemisphere observers, and from the southern hemisphere during the summer months. It is located south of Orion and Lepus, with other bordering constellations including Caelum, Pictor, and Puppis.
Heavenly Waters Family
Columba belongs to a family of constellations called the Heavenly Waters, most of which have some kind of watery association. These include Delphinus, Equuleus, Eridanus, Piscis Austrinus, Carina, Puppis, Vela and Pyxis.
Mythology
In 1592, Dutch astronomer Petrus Plancius formed Columba from a number of stars that were found behind Argo Navis, a now defunct constellation representing the ship belonging to the Greek mythological seafarer Jason. Plancius did so to honor the biblical story of the Great Flood, and the dove Noah sent from his Ark to look for dry land. The dove returned to the Ark with an olive branch clasped in its beak, giving Noah a sign that it had indeed found land, and that the waters of the Great Flood were receding.
However, Columba might also refer to the dove that was sent between the Clashing Rocks by Jason and the Argonauts to ensure their safe passage. Being located so close to the former constellation of Argo Navis, which represented the ship belonging to Jason, would seem to support a historical connection. Furthermore, a “dove” constellation was even mentioned by Clement of Alexandria as far back as the 2nd century BC, although he did not mention the precise stars he had studied. Argo Navis has since been abandoned, and in 1930 was broken up by the International Astronomical Union (IAU) into three separate constellations associated with Jason’s ship, namely Puppis (stern), Carina (keel), and Vela (sails).
Principal Stars
– Phact (Alpha Columbae), the brightest star in Columba, is a blue-white star (B7IVe) located around 270 light years from our solar system with a visual magnitude of 2.6. However, Phact is actually a double star whose main component is a subgiant Gamma Cassiopeia-type variable that has an expanding gas shell surrounding it. The name Phact derives from the Arabic word Al-Fakhita, meaning “ring dove”.
– Wezn (Beta Columbae), the constellation’s second brightest star, is an orange giant (K1IIICN+1) found about 86 light years distant of visual magnitude 3.12. Its name comes from an Arabic word meaning “the weight.”
– Ghusn al Zaitun (Delta Columbae) is a yellow giant found 238 light-years from the Sun that shines with an apparent visual magnitude of 3.85. Its name derives from the Arabic phrase al-ghusn al-zaitun, meaning “olive branch”. The star, however, is in fact a spectroscopic binary consisting of a yellow giant (class G7 II) and a smaller companion star that orbit each other once every 2.38 years.
Other notable stars in Columba include the orange giants Eta Columbae, Kappa Columbae, and Xi Columbae; and the blue-white stars Gamma Columbae, Lambda Columbae, and Theta Columbae.
Notable Deep-sky Objects
While Columba does not contain any Messier objects, it does have a handful of interesting deep-sky objects, including NGC 1808, a Seyfert galaxy found 40 million light years away that is similar in shape to our own Milky Way spiral galaxy. As well as the spiral galaxies NGC 1792 and NGC 2090, the constellation also includes the globular cluster NGC 1851 which is 35,000 light-years distant and shines with an apparent visual magnitude of 7.3.