SCORPIUS "The Scorpion" pronounced SKORP-yuss
This is a splendid constellation in a rich area of the Milky Way. It is one of the few constellations that bear a resemblance to the object after which it is named. In mythology, Scorpius was the scorpion whose sting killed Orion. In the sky Orion still flees from the scorpion, since Orion sets below the horizon as Scorpius rises.
The heart of Scorpius is marked by brilliant orange-red Antares, a name that means the rival of Mars (Ares).
North-east of β Scorpii, near the border with Ophiuchus, lies the brightest X-ray source in the sky, Scorpius X-1. This was the first X-ray source found outside the solar system.
A cluster of about twenty small stars around and including Antares is part of the Scorpio-Centaurus OB association, which is the closest aggregate of hot early-type stars to the Sun.
To find Scorpius look overhead in the late evening sky, and find orange-red Antares. Trace the sting and in the other direction, the three stars making the "head".
Chart showing Scorpius at about 9pm, 1 July and 7 pm, 1 August;
the head is to the northeast and the tail to the east.
Some stars and interesting objects in the Constellation
α Scoorpii (Antares, rival of Mars), is a red supergiant 330 light years away about 300 times the diameter of the Sun. It has a close 6th magnitude blue companion.
β Sco (Graffias, crab) is a striking double star easily divisible in the smallest telescopes. The two blue-white stars are magnitude 2.6 and 4.9 and lie 540 light years away.
ν Sco, is a quadruple star system 550 light years away. A small telescope shows ν Sco as a wide double, with blue-white companions of magnitude 4.0 and 6.3. Telescopes of 75mm and above reveal under high magnification that the fainter star is a close double of magnitude 6.8 and 7.8. The brighter star is an even closer double of magnitude 4.4 and 6.4. This last pair requires an aperture of over 150 mm to split them.
ξ Sco is a celebrated multiple star 85 light years away. This interesting system consists of a bright yellow pair, unfortunately just past minimum separation and unresolvable at present. There is a third star connected in a large orbit retrograde to the pair. In the same field 5' south-east is a smaller deep yellow pair with similar proper motion and radial velocity, indicating a physical connection.
M 4 (NGC 6121) is a large 7th magnitude globular cluster visible in binoculars. This beautiful cluster is crowded with stars running to a broad haze in the centre, across which is a bar of brighter stars. M 4 is the closest of all globular clusters to us at around 7,500 light years away.
M 6 (NGC 6405) the Butterfly Cluster, is an impressive 6th magnitude star cluster easily seen in binoculars, covering about the same area of the sky as the full Moon. The brightest member of the cluster is the orange-hued variable star BM Sco, which contrasts nicely with the other members of the cluster.
M 7 (NGC 6475) is a large, brilliant star cluster visible to the unaided eye, with an impressive diameter twice that of the Moon. Its 50 or so members are easily resolved in binoculars and small telescopes. The brightest stars are of magnitude 6 and appear to be arranged in chains.
M 80 (NGC 6093) is a small 8th magnitude globular cluster visible in binoculars or a small telescope, appearing like the fuzzy head of a comet. It lies about 36,000 light years away.
NGC 6231 is a large unaided eye glorious cluster of around 120 stars. It is a striking group for small telescopes. There are many bright white and yellow stars, and many pairs and triplets, which sparkle in patterns of lines and small groups. Its distance is estimated as 6000 light years. NGC 6231 is connected to a larger scattered cluster of fainter stars, visible in binoculars, called H 12, which lies to the north. The chain of stars linking NGC 6231 and H 12 outlines one of the spiral arms of our Galaxy.
NGC 6302 is a remarkable planetary nebula, popularly known as the "Bug Nebula". It is an elliptical or spindle-shaped bluish planetary nebula, with high surface brightness, appearing in a star-sprinkled field.
Scorpius is a southerly constellation with parts of the tail of the Scorpion passing overhead for places in New Zealand from about Christchurch northwards. Antares is at its highest at about 11.30 pm mid June, 9.30 mid July and 7.30 mid August.