A little ramble through Hydra the Water Snake

Hydra is the largest constellation in the sky but is by no means easy to find on account of its faintness. Hydra winds its way from the head in the northern hemisphere on the borders of Cancer to the tip of its tail south of the celestial equator near Libra and Centaurus.

There is a suggestion that Hydra it is part of the story of Jason and the Argonauts in that it represented the Dragon of Aetes helping to guard the golden fleece. The Hydra would be destroyed by Hercules.

It is possible that the Hydra was the snake depicted on a uranographic stone from the Euphrates dating to about 1200 BCE.

The Arab astronomer Al Sufi thought that the constellation was Al H’ail the Horse and was formed of stars that are now in Hydra but some also from Leo and Sextans

The Egyptians considered it the sky representative of the river Nile and gave it their name for the river.

Hydra has only one bright star Alphard which comes from the Arabic Al Fard al Shuja which means the Solitary One in the Serpent. Another Arabic name for Alphard was Al Fakar al Shuja which means the Backbone of the Serpent.

Tycho the last of the great pre telescopic astronomers called the star Cor Hydrae or the Hydra’s Heart in the 1590s.

Alphard is a magnitude 2.0 star the same brightness as the North Star but because it is not as high as the north Star it does not seem as bright. Alphard is 177 light years and is a K class star making it cooler than the Sun.

There are three Messier objects in Hydra.

Messier 48

An open cluster discovered by Messier in 1771 there is some confusion with M48 because the position given by Messier was not where M48 actually is. In 1783 Caroline Herschel, sister of William Herschel identified it, but the credit still goes to Messier. Sir John Herschel Caroline’s nephew described it “a superb cluster which fills the whole field; stars of 9th and 10th to the 13th magnitude – and none below, but the whole ground of the sky on which it stands is singularly dotted over with infinitely minute points

 M48 is 2,500 light years away shines at mag 5.8 and contains around 450 stars. A ;pair of binoculars will be needed to see it. 

Messier 68

A globular cluster discovered in 1780 , William Herschel described it "a beautiful cluster of stars, extremely rich, and so compressed that most of the stars are blended together". Its magnitude is 9.7 and is 33,000 light years away. A small telescope will be needed to find M68 

Messier 83

The Southern Pinwheel Galaxy so named because it looks like M101 the Pinwheel Galaxy in Ursa Major, it was discovered in 1781, it had been seen earlier by Nicolas Loius de Lacaille in 1752 from the Cape of Good Hope. M83 lies at a distance of 15 million light years. M83 shines with a mag of 7.5. A small telescope will be needed to see it.

Six supernovae have been observed in M83: SN 1923A, SN 1945B, SN 1950B, SN 1957D, SN 1968L and SN 1983N.

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A little ramble through the winter sky - Perseus

Perseus was the hero of Greek mythology who rescued Andromeda who was chained to a rock waiting to be eaten by the Kraken sea monster.  Previously he had killed the medusa.  The Gorgons eye is marked by Algol. Perseus lies in a rich part of the milky way and is worth sweeping with binoculars.

In 1901 a brilliant nova appeared in Perseus it reached magnitude 0.2 between delta and beta.

Near gamma lies the radiant for the Perseid meteor shower which occurs every August.

Alpha  or Algenib which means side  or is sometimes known as Mirfak the elbow. It has a magnitude of 1.8 and is a F class supergiant with a surface temperature of 6,300 degrees and is 510 light years away.

Beta or Algol which means the winking demon is an eclipsing binary star that John Goodricke studied from York in 1782, he realised that there were two stars there eclipsing each other causing the star to change in brightness. The eclipse occurs every 2.8 days and the magnitude varies between 2.2 – 3.5. Goodricke did not discover the variability that was done by the Italian astronomer Montanari in 1669. Algol lies at a distance of 90 light years and has a surface temperature of 13,000’C and is a B class star. The star which is eclipsing Algol cannot be seen with the naked eye.

Zeta has a magnitude of 2.9 and is a B class supergiant with a temperature of 20,500’C and is 750 light years away.

Epsilon also has a magnitude of 2.9 and is a B0. Class star. As hot as zeta is epsilon is even hotter with an incredible temperature of 26,000’C and is 640 light years away. Both zeta and epsilon will probabably end their lives in a massive supernnva explosion.

Rho a semi regular variable varying between magnitude  3.3 and 4.0 in  aperiod or around 50 days. Its a M class red giant with a temperature of 3,800’C and is 308 light years away.

NGC 869 and NGC 884  Mag 3.7 the famous double cluster sometimes also known as chi perseus. These are open clusters with 350 and 300 stars respectively, lying about 7,600 ly away and about 300 light years apart.   NGC 869 and 884 are of magnitude 3.7 and 3.8 respectively, which in binoculars resolves into a grand pair of bright stellar star fields about 0.5 degrees apart. Each cluster contains over 300 blue white super giant stars. They are about 7,500 light years away.  

The letters NGC refer to the New General Catalogue of galaxies and star clusters and was introduced in 1888. Although its name is the New General Catalogue we still use that term today.  

In the 18th century the French astronomer Charles Messier was looking for comets with his small telescope. Although he found around a dozen comets none were very bright. Messier did however come across many fuzzy comet looking objects that  were not comets. He produced this list of noin comet objects whcih today is referred to as the Messier list of non comet objects and is used by astronomers. Its ironic that his comets are forgotten but his list of non comet objects has not been forgotten.                              

 While it was curious that Messier overlooked the double cluster maybe it was too obviously not a comet, he did however discover another open cluster in Perseus, this is M34 glimmering at mag 5.5 just visible to the naked eye to the right of Algol.

M34 is a loose aggregation of about 60 stars, M 34 is about 100 million years old, much older than the double cluster. M34 is only spread across about 10 light years. It is a wonderful sight in binoculars or small telescopes.

It was seen by Messier in 1764 who described it as a faint cluster of stars between the head of medusa and the left foot of Andromeda. The stars may be detected with a simple telescope.

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A little ramble through 19th century astronomy - Rio de Janeiro 1874

 Nature June 11^th 1874

Les Mondes announces the death of Mme. Liais, the wife of the director of the Observatory of Rio de Janeiro, who acted as the secretary of and co worker with her husband in all his labours. She accompanied him in his dangerous expeditions into the centre of Brazil, and died in consequence of the sufferings she endured during her travels with her husband.

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Cooke Telescope Tales - a number of telescopes for London

Edmund Wheeler a lecturer (I don’t know in which subject) of London in 1857 purchased a number of telescopes from Thomas Cooke & Sons. 

In February a 2.75 inch was brought, while in May a 4 inch engraved ‘Edmund Wheeler London’ and finally in September a 4 inch telescope on a plain equatorial stand with brass finder, 4 astronomical eyepieces and a sun prism. The cost of this telescope was £40. 

In 1864 the 4 inch which was not engraved was being sold for £40. This was the same price that the telescope was brought for.

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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.

A little ramble through astronomy in Yorkshire - Thornborough Henge

 We now travel back in time not this time in millions but in thousands of years to around 3,500 BCE (Before Christian Era) to discover one of the most important ancient sites in Britain, this is the Thornborough Henges. They are located near the village of Thornborough which is in the Hambleton district of North Yorkshire near to Bedale. The henges consist of a series of three circular mounds with ditches and banks that were probably in use for over a thousand years. This site is often referred to as the ‘Stonehenge of the North’.

Thornborough Henge is the world’s only triple henge with the length of the three circles covering a distance of about one mile.  The henges are aligned northwest to southeast and laid out at approximately 550m apart.  All are of similar size and shape, have a diameter between 240 and 275 metres, and stand some three meters in height. We cannot be sure why it was built some astro archaeologists think that Thornborough may have been a pilgrimage centre where people sought spiritual salvation and that it served an economic and social needs however there does appears to be a definite astronomical connection.

The Thornborough Henges align with one of the most famous star patterns in the sky, Orion’s Belt.  The henges do not form a straight line but instead were intentionally shaped like a ‘dog leg’ to reflect the shape that the stars of Orion’s belt form in the sky. The constellation of Orion is very well known and is one of the two main signposts in the sky which help astronomers to find their way around while learning the positions of the stars in the night sky. The other is the Plough or Big Dipper as the Americans prefer to call it. The Plough is part of the constellation of Ursa Major the Great Bear, and while the Plough is visible all year around while in Britain Orion can only be seen in the winter sky.

Orion is one of 88 constellations recognised today be astronomers today. These are just like giant pictures in the sky and if you can find them it is possible to start reading the stories they are telling us. Of these 48 were designed by the Greeks and therefore by convention we tend to use the Greek myth and legends attached to them. Most other civilisations had their own versions of the ones we use here in the west. The other 40 constellations were added from the sixteenth century onwards by astronomers filling in the gaps between the main star groups in the northern hemisphere. When European explorers travelled into the southern hemisphere, they saw stars that cannot be seen in Europe so created a series of constellation in the southern sky. Many of these are depictions of what were at the time newly invented scientific instruments. This explains why in the southern hemisphere we see constellations such as Telescopium the Telescope and Microscopium the Microscope. The vast majority of these modern constellations both in the northern and southern hemispheres are comprised of faint and obscure stars. 

Orion on the other hand is a magnificent constellation easily recognised by four bright stars that form a large rectangle in the sky inside which are the three stars that form Orion’s Belt. The top left-hand star of the rectangle is the famous red star Betelgeux which is often called Beetlejuice!  As we look at the belt stars from left to right they are Alnitak, Alnilam and Mintaka.  The stars names may seem a little different to us this is because they are Arabic. When we translate the stars of Orion’s belt into English, we discover that Alnitak means The Girdle, Alnilam the String of Pearls and Mintaka is the Belt.

This same astronomical alignment can be found in the great pyramids in Egypt, but the Thonrborough Henges are about 1,000 years earlier than the Egyptian pyramids. This could be the first known monument to align with the constellation of Orion. Was this co- incidence that the people of Yorkshire and those in Egypt created the same pattern on the ground or maybe people travelled around the world thousands of years ago exchanging thoughts, ideas and customs? 

The structures of the henges were aligned so its western end pointed towards the mid-winter setting of Orion which also meant that the eastern end aligned towards the midsummer solstice.

Today we talk about light pollution and how difficult it is for people who live in cities to see the stars properly.  We can be certain that the night skies were much darker when the henges were constructed over 5,000 years ago, there would be no light pollution at all. Today Orion is still an amazingly wonderful constellation to look at but with darker skies it must have looked even more impressive, and this perhaps is one of the reasons why they had such a fascination for this one particular group of stars.

Today, all three of the Thornborough Henges, as well as the land connecting them together, are listed as Scheduled Ancient Monuments.

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Cooke Telescope Tales - comet seen from Gibraltar in 1860

 Colonel De Rottenburg wrote in a letter dated June 24^th, 1860, from Gibraltar. “I observed a brilliant comet in the constellation of Auriga this evening, a line from beta through a Geminorum continued about three times their distance passed through its nucleus. 

It was easily seen with the naked eye; the nucleus was a little less brilliant than Castor. Its altitude above the western horizon about equal to that of Venus at the same time. 

I turned my 6 feet equatorial of 4.5 inches aperture made by Messrs Thomas Cooke & Sons of York on the comet. 

It has a bifid tail, very like that of the year 1846 as shown in Keith Johnsone’s Atlas of Astronomy which is edited by Mr Hind. I used powers of 26, 50 and 100 on the comet; the nucleus has a very sensible disk. It bore the powers of 100 very well; one portion of the tail is much longer than the other, the south preceding being the longer. 

With 100 power the nucleus was situated within the nebulosity, and the nebulosity was more arched and prominent on the south preceding part. It was first seen by a gentleman here on Saturday evening 23^rd June.

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