Ophiuchus and the supposed thirteenth star sign

Every few years the same story does the rounds in the news: astronomy is said to have found a thirteenth star sign, every horoscope is void as a result, and you are not really a Scorpio at all. A few days of excitement, then the matter disappears again — until the next time. Behind it there is a real constellation with a fine story, and a misunderstanding that a few sentences will clear up.

Who Ophiuchus is

Ophiuchus, the Serpent Bearer, is a large but rather inconspicuous constellation of the summer sky, north of Scorpio. It shows a man holding a serpent in both hands. The serpent counts as a constellation of its own and lies divided on either side of him: the head to the west, the tail to the east. Its brightest star carries an Arabic name, Rasalhague, and that means nothing other than the head of the snake charmer.

In ancient tradition the figure is Asclepius, who knew the art of healing. His staff with the serpent on it has remained to this day the sign of pharmacies and of the medical professions. The serpent sheds its skin and comes out renewed — in this story it is therefore not a horror but an image of recovery. A character portrait of an Ophiuchus type, incidentally, is not to be found in it: the story tells of a healer, not of people born under him.

That the Sun passes through it is no news

The ecliptic — the line along which the Sun travels across the sky in the course of a year — does indeed graze Ophiuchus. Between Scorpio and Sagittarius it runs a good stretch through his territory, for a good two weeks. That is on every star chart and it is no discovery of the last few years; it can be worked out to the day, and has been ever since the boundaries of the constellations were officially fixed. The only new thing about the story is how reliably it comes back.

A constellation is not a sign

A constellation is an area of the sky, and these areas differ greatly in size. Their present boundaries were laid down by the International Astronomical Union in the twentieth century, along clean lines of coordinates. The result: in one constellation the Sun spends only a few days, in another well over a month. As a division of the year that is of no use.

A zodiac sign is something else: a stretch of exactly thirty degrees on the ecliptic, counted from the spring equinox. Twelve times thirty degrees make the full circle. This division comes from Babylon, it is some two and a half thousand years old, and it borrowed its names from the constellations that stood roughly in those places at the time. It was never more than a kinship of names. That is why the question of which constellation the Sun really stands in today is beside the point: a sign is a measure, not a picture.

Thirteen would not work arithmetically

Suppose for a moment that someone seriously wanted to cut the circle into thirteen parts. The whole framework that interpretation hangs on would collapse. Twelve divides into halves, thirds and quarters: two polarities, three modes, four elements, six axes of two opposite signs each. Thirteen is a prime number. There would be no opposite sign any more, no groups of three sharing an element, no division into active and receptive — and with that nothing left of what is described under four elements. Twelve is also the number that fits the year: the Moon comes to the full about twelve times while the Sun goes round once.

Nothing changes for your chart

The positions of the Sun, the Moon and the planets at the moment of your birth are measured quantities. They are fixed, quite regardless of how many figures anyone draws on the sky. A newspaper story shifts not a single degree. What your sign says in detail you can read under zodiac signs, and how it works together with the rising sign under ascendant.

Ophiuchus loses nothing in all this. He remains a large constellation with a healer, a serpent and one of the finest star names in the sky — take a look at him on a clear summer night.