Tukuk-OS✨ Corona Australis
CrA · southern crown · Southern sky
Corona Australis is one of the 88 modern constellations defined by the International Astronomical Union. Its name is Latin, meaning southern crown; stars within it are named in the genitive form Coronae Australis.
Facts about Corona Australis
| Constellation | Corona Australis |
|---|---|
| IAU abbreviation | CrA |
| Genitive (Latin) | Coronae Australis |
| Meaning | southern crown |
| Brightest star | Meridiana (apparent magnitude 4.09) |
| Area | 128 square degrees |
| Hemisphere | Southern |
How big is Corona Australis on the sky?
With an area of 128 square degrees, Corona Australis is number 80 of 88 constellations by size — 0.3% of the whole celestial sphere. That is roughly 640 full moons of sky side by side (the Moon’s disc covers about 0.2 square degrees). The ranking runs from Hydra, the largest at 1,303°, down to Crux, the smallest at 68°; Corona Australis sits between neighbours Triangulum (132°) and Caelum (125°).
It is worth remembering what those borders are: since 1922 the IAU has drawn the 88 constellations as precise regions tiling the entire sky, so every star, every galaxy and every empty patch belongs to exactly one of them — ancient figures, modern surveying.
The name in use
Stars and variable objects inside Corona Australis are labelled with its genitive (possessive) form, Coronae Australis: the Bayer designations run Alpha, Beta, Gamma… Coronae Australis, and deep-sky objects are often called “of Coronae Australis” in catalogues and papers. The Greek letters roughly follow brightness but do not always obey it — history, not rules, decided which star got Alpha. The Latin meaning of the name is southern crown; southern skies carry its brightest members, of which Meridiana shines at apparent magnitude 4.09.
Who can see it: a southern-sky constellation: from mid-southern latitudes it rides high, and from far north of the equator it never properly rises. From the equator, in the course of a year, well-nigh every constellation in the catalogue crosses the sky — the further you travel from it, the more of the opposite hemisphere you permanently leave behind.