What it looks like
Ophiuchus is a large constellation in the equatorial region of the sky, drawn as a man holding a serpent. It sits between Hercules and Scorpius, and the Sun passes through it for about 18 days each year, longer than it spends in Scorpius.
Brightest stars
Ophiuchus has one second-magnitude star, Rasalhague, plus several third-magnitude stars that form the serpent-bearer's body.
| Star | Magnitude | Distance | Meaning |
|---|---|---|---|
| Rasalhague (α Ophiuchi) | +2.07 | 49 ly | Head of the Serpent Bearer |
| Sabik (η Ophiuchi) | +2.43 | 88 ly | — |
| Zeta Ophiuchi | +2.54 | 366 ly | — |
| Yed Prior (δ Ophiuchi) | +2.74 | 171 ly | The Hand |
| Cebalrai (β Ophiuchi) | +2.76 | 82 ly | Dog of the Shepherd |
Mythology and history
In Greek myth, Ophiuchus represents Asclepius, the healer who learned the secret of resurrection from a serpent and was killed by Zeus for it.
Asclepius and the serpent
Asclepius was the son of Apollo and a mortal woman, trained in medicine by the centaur Chiron. When he saw a serpent revive another with a herb, he learned to bring the dead back to life. Hades complained to Zeus that this upset the order of things, and Zeus struck Asclepius down with a thunderbolt. In honour of his skill, he was placed in the sky holding the serpent, and his staff — the Rod of Asclepius — remains a symbol of medicine today.
The 13th zodiac
Because the ecliptic passes through Ophiuchus, the Sun spends about 18 days in the constellation each year. Babylonian and later astronomers acknowledged this, but the twelve-sign zodiac was kept for convenience of twelve equal 30-degree divisions.
How to find it
Look for a large, roughly rectangular figure between Hercules and Scorpius on summer evenings, with Rasalhague at its northern tip.
- Find Rasalhague above Antares in Scorpius.
- Trace the long body down toward Scorpius.
- Best on summer evenings from both hemispheres.
Key facts
- Abbreviation
- Oph
- Genitive
- Ophiuchi
- Meaning
- The Serpent Bearer
- Brightest star
- Rasalhague
- Main stars
- 10
- Area rank
- 11th
- Best visible
- July
- Declination
- 0°
- Meteor showers
- Ophiuchids, Northern May Ophiuchids, Southern May Ophiuchids, Theta Ophiuchids
- Neighbours
- Hercules, Serpens Caput, Libra, Scorpius, Sagittarius, Serpens Cauda, Aquila
Deep-sky objects
Ophiuchus lies toward the Milky Way's centre and is rich in globular clusters, including M9, M10, M12, M14, M19, M62 and M107. The Dark Horse Nebula, a large dark nebula, sits in the constellation's southern reaches, and Barnard's Star — the nearest single star to the Sun — lies in Ophiuchus.
Frequently asked questions
What does the constellation Ophiuchus look like?
Ophiuchus is a large constellation known as the Serpent Bearer, straddling the celestial equator and crossed by the ecliptic — which is why it is sometimes called the 13th zodiac sign.
What is the brightest star in Ophiuchus?
The brightest star in Ophiuchus is Rasalhague, shining at around magnitude 2.07.
When is Ophiuchus best visible?
Ophiuchus is best seen from both hemispheres during July.
What is the story behind Ophiuchus?
In Greek myth, Ophiuchus represents Asclepius, the healer who learned the secret of resurrection from a serpent and was killed by Zeus for it.
Which constellations are near Ophiuchus?
Ophiuchus borders Hercules, Serpens Caput, Libra, Scorpius, Sagittarius, Serpens Cauda and Aquila.
Scorpius
Hercules