- Star Tales - Columba (ianridpath.com)
A constellation formed in the late 16th century by the Dutch cartographer and astronomer Petrus Plancius, who took some stars that Ptolemy in his Almagest had catalogued as lying outside Canis Major. These unformed stars can be seen, for example, on the southern half of Albrecht Dürer’s star chart of 1515 as two little groups, one group of six to the south of Lepus, from which the dove was formed, and another group of five between the hind legs of Canis Major which Plancius visualized as an olive branch.
- Local Group (Wikipedia)
The Local Group is the galaxy group that includes the Milky Way. It has a total diameter of roughly 3 megaparsecs (10 million light-years; 9×1022 metres), and a total mass of the order of 2×1012 solar masses (4×1042 kg). It consists of two collections of galaxies in a “dumbbell” shape: the Milky Way and its satellites form one lobe, and the Andromeda Galaxy and its satellites constitute the other. The two collections are separated by about 800 kpc (3×106 ly; 2×1022 m) and are moving toward one another with a velocity of 123 km/s. The group itself is a part of the larger Virgo Supercluster, which may be a part of the Laniakea Supercluster. The exact number of galaxies in the Local Group is unknown as some are occluded by the Milky Way; however, at least 80 members are known, most of which are dwarf galaxies.
- Columba (constellation) (Wikipedia)
Columba is a faint constellation designated in the late sixteenth century, remaining in official use, with its rigid limits set in the 20th century. Its name is Latin for dove. It takes up 1.31% of the southern celestial hemisphere and is just south of Canis Major and Lepus.
