Tukuk-OS✨ Aries
Ari · ram · Northern sky
Aries is one of the 88 modern constellations defined by the International Astronomical Union. Its name is Latin, meaning ram; stars within it are named in the genitive form Arietis.
Facts about Aries
| Constellation | Aries |
|---|---|
| IAU abbreviation | Ari |
| Genitive (Latin) | Arietis |
| Meaning | ram |
| Brightest star | Hamal (apparent magnitude 2) |
| Area | 441 square degrees |
| Hemisphere | Northern |
How big is Aries on the sky?
With an area of 441 square degrees, Aries is number 39 of 88 constellations by size — 1.1% of the whole celestial sphere. That is roughly 2,205 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°; Aries sits between neighbours Canes Venatici (465°) and Capricornus (414°).
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 Aries are labelled with its genitive (possessive) form, Arietis: the Bayer designations run Alpha, Beta, Gamma… Arietis, and deep-sky objects are often called “of Arietis” 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 ram; northern skies carry its brightest members, of which Hamal shines at apparent magnitude 2.
Who can see it: a northern-sky constellation: from mid-northern latitudes it rides high, and from far south 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.