The celestial Wolf: the Centaur's beast and the wolves that chase the Sun

In the southern sky, low on the horizon for observers in Italy, lies a constellation with a curious past. Today we call it Lupus, the Wolf, but for most of antiquity it had no precise name: it was simply a beast, a wild animal held in the arms of the Centaur. Its story shows how the figures of the sky can change identity over the centuries, and how the wolf found a place among the stars in other traditions too.

The nameless beast

Aratus, in the Phaenomena, describes the Centaur holding an animal in his right hand, turned towards the Altar. Ptolemy, in the Almagest, calls this constellation Therion, that is, “the wild beast”, without specifying which animal it is. Latin translations rendered the term with generic words such as Bestia, and the name Lupus became established only later, in medieval and Renaissance star catalogues.

The ancient image is that of a sacrifice: the Centaur, often identified with the wise Chiron or with Pholus, carries the animal towards the celestial altar, the constellation Ara, as an offering to the gods. Some authors interpreted the scene as an act of religious piety, consistent with the figure of Chiron, teacher of heroes and expert in the stars.

Long before the Greeks, Babylonian astronomical lists knew in this area of the sky a figure called by a term that scholars translate as “wild dog” or “wolf”. Continuity between the two traditions is not certain, but the idea of a fierce animal in this region of the sky seems very old.

The new star of 1006

In the spring of 1006 a sudden and dazzling star appeared in Lupus, the brightest supernova ever recorded in history. It was observed and described in Egypt by the physician and astronomer Ali ibn Ridwan, in China and in Japan, and the annals of the monastery of St Gall, in Switzerland, also mention it. According to the accounts, its light made it possible to see objects at night.

Chinese astronomers recorded it as a “guest star”, the name they gave to bodies that appeared temporarily. Today astronomers have identified the remains of that explosion, an expanding cloud of gas that preserves the trace of an event a thousand years ago. Thus a little-known constellation has become important in the history of astronomy.

The wolves that chase the Sun

In Norse mythology, as recorded in the Prose Edda of Snorri Sturluson, written in the thirteenth century, the Sun and the Moon race across the sky because they are pursued by two wolves, Sköll and Hati. At the end of time, at Ragnarök, the wolves will catch the heavenly bodies and devour them. The great wolf Fenrir, son of Loki, is instead destined to break his chains and fight against Odin.

The celestial wolf thus crosses cultures and centuries, now an animal to be offered on the altar, now a hunter threatening the Sun. In Greek tradition the wolf was also linked to Apollo, worshipped with the epithet Lykeios, and to the myth of Lycaon, turned into a wolf by Zeus. In the sky, the small southern constellation preserves the memory of this long and ambivalent history.