A little ramble through Ophiuchus the Serpent Bearer

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.

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The Astronomy Show on Drystone Radio

 Join me, Martin Lunn MBE every Monday evening from 7.00 pm-9.00 pm on the award-winning Astronomy Show on Drystone Radio, probably the only regular astronomy show on any radio station in the country. 

I will take my weekly look at the night sky and look at all the latest news in astronomy. There will be the astronomical anniversaries this week plus the latest news from the astronomical societies in the north of England.

The Astronomy Show every Monday evening only on Drystone Radio live online at www.drystoneradio.com DAB radio in Bradford and East Lancashire, or 102 and 103.5 FM and can also be heard later on the Drystone Radio Podcast.

Cooke Telescope Tales - Maurice Farman and the Chevreuse Observatory in 1908

As far as I am aware this is the not the same Maurice Farman who was an early pioneer in the days of flight, but I am always ready to be proved wrong.

 In 1908 while observing at the Chevreuse Observatory near Paris, an observatory I have never heard of before observed 1,100 double stars while using a 9.5 inch Cooke telescope.  

His observations were apparently quite brief and usually consisted of just one line of information, many additional notes  were drawn from historical observations of the stars he observed in 1908.

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Cooke Telescope Tales - transit of Mercury seen from Mauritius in 1907

The transit of Mercury was observed on November 14^th 1907 from the Royal Alfred Observatory in Mauritius using a Cooke 6 inch refractor. The transit which was seen through a partly  cloudy sky and the limb of the Sun was described as being boiling. Mercury appeared as a clear cut black disc, perfectly circular with no spot or fringe. 

There were 11 photographs taken during the transit with the 6 inch Cooke. The telescope  had ben supplied to Mauritius by the colonial government in1874 in order to observe the transit of Venus.

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Cooke Telescope Tales - The disorderly apprentice in 1859

 On Thursday November 3^rd 1859 J Chadwick esq apprentice summoned Mr Cooke, optician and mathematical instrument maker to the magistrates at the Guildhall in York for refusing to teach him his grade. 

Mr Cooke said that J Chadwick had grossly misbehaved and had absented himself on one or two occasions. Under these circumstances Mr Cooke refused to receive the lad into his service. 

The magistrate ordered the lad’s indentures to be dismissed. J Chadwick has since joined the Cape Mounted Rifles in South Africa.

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A little ramble through Octans the Octant

 Octans the Octant-Southern Hemisphere

The constellation that contains the South Pole star, despite this privileged position, Octans is faint and unremarkable. There is no southern equivalent of Polaris, the North Pole star. The nearest star to the south celestial pole is Sigma Octantis with a magnitude of only 5.5 which lies about 1 degree from the pole. 

The constellation of Octans commemorates the instrument known as the Octant, a forerunner of the sextant, invented by the English astronomer John Hadley and used by him for measuring star positions.

The constellation was introduced by Nicolas Lacaille during his stay at the Cape of Good Hope and its dullness is a memorial to his dreadful lack of imagination.

There are a few northern references to a south pole star, the Hindu’s referred to it as Dramasa, while the Arab astronomers either knew or guessed that there would be a south pole without giving it a name.

The brightest star is Nu an orange K class giant star with a brightness of magnitude of 3.7 lying at a distance of 64 light years.

Sigma the South Pole Star shines with a brightness of magnitude 5.5 and lies at a distance of 281 light years. Sigma is a F class giant star with a temperature of 7,200’C.

Cooke Telescope Tales - telescope for Macclesfield in 1864

Thomas Davenport of Macclesfield purchased from Thomas Cooke in 1864 a small telescope. It had a lens of 2.5 inches and came with a terrestrial eyepiece and leather sling case. I assume this was not for astronomical work. 

Davenport later in 1868 purchased from Thomas Cooke a brass pillar and claw table stand and two astronomical eyepieces. I don’t know if this was to mount the telescope he purchased in 1864 or if it was for another instrument.

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