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OPHIUCHUS, pronounced OFF-ee-YOO-kuss and SERPENS pronounced SUR-penz

Chart showing the constellations.

Ophiuchus is an ancient constellation representing a man coiled by a serpent (the constellation Serpens). Ophiuchus is identified by some as Aesculapius a mythical healer and forerunner of Hippocrates. Aesculapius served as ship's doctor on the Argo of Jason and the golden fleece legend. Another interpretation sees this constellation as Enkidu, the companion of Gilgamesh, who circles head-to-head with Ophiuchus in the sky, in the form of the constellation Hercules. The most celebrated star in Ophiuchus is a 9th magnitude red dwarf star, too faint to be seen with the unaided eye.

Barnard's Star at 6 light years away is the 2nd closest star to the Sun. Barnard found in 1916 that it has the greatest proper motion of any star; it appears to covers a distance equal to the diameter of the Moon every 180 years. The southern regions of Ophiuchus extend into the rich star fields of the Milky Way, looking towards the centre of the Galaxy. Ophiuchus was the site of the last supernova seen to erupt in our Galaxy in 1604.

Serpens represents the serpent wound round Ophiuchus. Serpens is split into two halves: Serpens Caput, the head; and Serpens Cauda, the tail.

To find Ophiuchus and Serpens look towards the North about half way between the horizon and the zenith. Ophiuchus is suppose to look like a teapot but to us that object will be upside-down.

Chart showing Ophiuchus and Serpens as seen in the sky to the north mid evening in August.

Ophiuchus and Serpens

Constellation Libra Constellation Scorpius Constellation Sagittarius Constellation Scutum Constellation Aquila Constellation Hercules

Some stars and interesting objects in the Constellation

α Ophiuchi (Ras Alhague, head of the serpent charmer) is a magnitude 2.1 white star 62 light years away.

α Serpentis (Unakalhai, serpent's neck) is a magnitude 2.7 orange giant star 85 light years distant.

M 10 (NGC 6254) is a 7th magnitude globular cluster about 19,000 light years away, visible in binoculars and small telescopes. Larger telescopes will begin to resolve individual stars in the cluster, showing two straight rays of four or five stars to the north.

M 12 (NGC 6218) is another 7th magnitude globular cluster slightly closer than M 10. It appears slightly larger than M 10 and has a more loosely scattered appearance.

M 5 (NGC 5904) is a 6th magnitude globular cluster 27,000 light years away, visible in binoculars or small telescopes. It is regarded as one of the finest globular clusters in the northern sky. Reasonable sized telescopes reveal a brilliant condensed centre and apparent chains of stars radiating outwards. Close by is 5 Serpentis, a 5th magnitude star with a 10th magnitude companion.

M 16 (NGC 6611) is an irregular, hazy looking cluster about 8,000 light years away. It consists of about 50 stars of 8th magnitude and fainter in an area about the apparent diameter of the Moon, embedded in a nebula known as the Eagle. The Eagle nebula is a famous Hubble telescope picture showing star formation from a dusty cloud. The Eagle nebula while faint, is made more visible with an OIII or other nebula filter.

NGC 6633 is a bright irregular scattered cluster of about 65 stars about 1,600 light years away, visible in binoculars, or even the unaided eye from a dark sky site.

IC 4665 is a loose and irregular cluster of a dozen or so stars of magnitude 7 or fainter, about 1,000 light years away requiring a wide field, such as binoculars. There is a "Y" shaped asterism in the north-eastern portion of the cluster.

NGC 6572 is a 10th magnitude planetary nebula, 2,500 light years away, visible in a telescope as a tiny blue-green ellipse.

Alya, θ Serpentis is an elegant pair of white stars magnitude 4.1 and 5.0, 100 light years away. There is an orange star slightly (7') north east, contrasting with the attractive wide pair.

Visibility

Ophiuchus and Serpens are visible to the north from New Zealand at about 9.30 pm NZST on August 1, 8.30 pm August 16 and 7.30 pm August 31.
During July the two constellations are to the north-east in the early evening, moving to be to the north by about 11.30 pm July 1 and 10.30 pm mid July.
During September and early October the constellations will be to the north-west shortly after the sky gets dark in the evening.  They are low to the west in the evening twilight by mid October and are lost in the evening twilight by the end of the month.