Columba (constellation)

Columba is a faint constellation located in the southern celestial hemisphere. Its name is the Latin word for dove. This constellation covers 1.31% of the southern sky. It sits just south of the constellations Canis Major and Lepus. While it is not a very bright group of stars, it is an official part of our map of the heavens.

The stars within Columba are generally difficult to see with the naked eye. The brightest star is Alpha Columbae, which has a magnitude of 2.7. This is a blue-white star located 268 light-years from Earth. It carries the traditional Arabic name Phact, which means "ring dove." Another notable star is Beta Columbae, also known as Wazn. This is an orange-hued giant star with a magnitude of 3.1. It is much closer to us than Alpha Columbae, sitting only 87 light-years away.

Astronomers have noted the stars in this region for many centuries. An early 3rd-century BC poem called Phainomena by Aratus mentioned faint stars in this area. However, the poem did not assign them a specific name or shape. In the 2nd century AD, Ptolemy listed 48 constellations in his work, the Almagest. While Columba was not one of them, several stars that now belong to it were listed south of Canis Major. Centuries later, the writer Clement of Alexandria mentioned a dove as a symbol for Christians, though he did not speak of astronomy.

The modern shape of Columba began to take form in the late sixteenth century. In 1592, Petrus Plancius first depicted the constellation on celestial planispheres. He used it to organize the "unformed stars" near the large constellation Canis Major. Plancius called it Columba Noachi, or "Noah's Dove." This name refers to the dove that told Noah the Great Flood was receding. This specific name appeared on many early 17th-century star atlases and celestial globes.

Different explorers and astronomers added to our understanding of Columba over time. In 1603, Frederick de Houtman called it "the dove with the olive branch." That same year, Johann Bayer published the Uranometria sky atlas, which included Columba as Columba Noachi. Later, in 1679, Edmond Halley mentioned the constellation in his catalog of southern stars. Between 1757 and 1763, the astronomer Lacaille officially listed Columba as a constellation. He catalogued 17 stars for the group, though he omitted some and mislabeled others.

Columba contains several interesting celestial objects and phenomena. It is home to a globular cluster known as NGC 1851. This cluster is located 39,000 light-years away in a far part of our galaxy. It has a magnitude of 7 and can be seen through medium-sized amateur telescopes. The constellation also contains the star NGTS-1 and its exoplanet, NGTS-1b. Additionally, Columba contains the solar antapex. This is the direction that is exactly opposite to the net direction of our Solar System's movement.

Recent discoveries continue to reveal the secrets of this faint constellation. In 2019, students working with the OSIRIS-REx mission discovered a black hole within Columba. They identified it by observing specific X-ray bursts. This discovery shows that even quiet-looking parts of the sky can hold powerful objects. The study of Columba connects our history of star mapping to modern high-energy physics. By looking at these dim stars, we learn about the movement of our sun and the distant reaches of our galaxy.