Ophiuchus is one of three large constellations visible in the summer months in the southern part of the sky, the others being Hercules and Serpens which are all formed of faint stars.
Ophiuchus is an ancient constellation depicting an elderly man encoiled by a serpent. In the night sky
today, Ophiuchus clearly had the best of the struggle with the serpent as it is
n ow depicted in two halves one being the body of the serpent the other being
its head.
He is identified to
the Greeks as a mythological forerunner of Hippocrates who served as the ship’s
surgeon aboard the ship the Argo., with Jason looking for the golden fleece.
It was said the medical work of Ophiuchus was so great he
could bring the dead back to life. He tried but failed to b ring Orion back to
life after he had been stung by a scorpion.
In Rome, Pliny considered that the stars that formed
Ophiuchus were dangerous to mankind through the killing of people by poisoning.
The brightest star alpha is known as Rasalhague which means ‘Head of the Serpent Charmer’ it has a magnitude of mag 2.1 and is an A class giant star with a surface temperature 7,500’C which is much hotter than the Sun. Rasalhague is 47 light years away.
Eta or to the Arabs Saik or the Driver is of magnitude 2.4
and is 88 light years away. It is an A class star with a temperature of 9,600’C
Beta or Alrai which means The heart of the Shepherd is a
magnitude mag 2.8 star lying 82 light years away. Alrai is a K class giant star
with a surface temperature of 4,100’C.
Delta or Yed Prior which means ‘Hand’ is of magnitude 2.8
and is a M class red giant with a temperature of 3,400’C lying at 171 light
years away. In China the star is known as Leang or Mast.
In 1604 Johannes Kepler saw a supernova in Ophiuchus, a
supernova is a star that destroys itself in a massive explosion. the last easily This was the last bright
supernova to be seen in our galaxy. It reached a magnitude of -2.1 and was
visible to the naked eye for around 18 months. This was before the first use of
the telescope for astronomical uses which was in 1609.
Probably the most famous star in Ophiuchus is one that
cannot be seen without binoculars or telescopes this is Barnard’s star a 9th
magnitude star only 6.1 light years away, the fourth closest to the Sun after
the 3 stars in the alpha centauri group. It was found by Edward Emmerson
Barnard in 1916. It is a red dwarf star.
There are a large number of Messier objects in Ophiuchus
Messier 9
Globular cluster discovered in 1764 mag 9.3 one of the
closer globular at a distance of 5,500 light years.
Messier 10
Globular mag 6.4 discovered in 1764 diameter of 83 light
years 13,400 light years
Messier 12
Globular discovered in 1764 15,700 light years away mag 7.7
diameter 75 light years
Messier 14
Globular cluster mag 7.6 30,000 light years away and 100
light years across
Messier 19
Globular cluster discovered in 1764 mag 7.5 28,000light
years across
Messier 62
Globular cluster discovered in 1771 magnitude 6.4 and 22,000
light years away
Messier 107
Globular cluster probably seen by Messier in 1782 and is
21,000 light years away and is of magnitude 8.9
The following are not in the |Messier list
IC 4665
An open cluster at mag 4.2 visible to naked eye, also binoculars
or small telescope. For some reason it was not catalogued by messier it lies at
1,400 light years away and is about 40 million years old.
NGC 6633
Open cluster mag 4.6 again not catalogued by Messier it
contains about 30 stars and is around 660 million years old.
Although not classified as a zodiacal constellation
Ophiuchus does lie in the zodiac. It can be found between the constellations of
Sagittarius and Scorpio. This means that there are times when planets can be
found passing through Ophiuchus.
www.theramblingastronomer.co.uk
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