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 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.

Andromeda’s mother Cassiopeia had upset Neptune god of the sea who then sent a monster the Kraken to attack her land. She was told the only way to save her land as to chain her daughter Andromeda to the Rocks and let the Kraken eat her.

Andromeda was chained to the rocks the monster appeared everything appeared lost but at the last-minute Perseus appeared riding the winged horse Pegasus. He had just killed the Medusa, a monster so horrible that anyone who looked at it would turn to stone. The medusa’ s hair was made of snakes. Perseus still had the head of the monster, he showed it to the Kraken which turned to stone. Perseus landed rescued Andromeda. They were married and lived happily ever after.

The Arab astronomers sometimes referred to Perseus as Hamil Ra’s al Ghul or the Bearer of the Demon’s Head.

The brightest star alpha has two given names Algenib which means Side or which can mean 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 marks the eye of the medusa and its name is Algol which means the Winking Demon. It’s not one star but two which are eclipsing each other. This causes the brightness of the star to change. Astronomers call stars that change in brightness Variable Stars. This variability can be caused by several factors. The name Algol is interesting because the name might suggest that Arab astronomers 1,000 year ago knew it changed in brightness or winked in the sky. Sadly, we have no proof for this idea, yet.

This change in brightness of Algol was noted by the Italian astronomer Montanari in 1669. It would however not be until 1782 that the cause of the variability of Algol would be explained. It was the deaf astronomer John Goodricke who lived in York and  who explained what was happening to Algol.

Although he was deaf there was nothing wrong with his brain, he was very clever. He worked with another astronomer in York, Edward Pigott between 171-1786 when Goodricke died, they discovered and suggested what was causing light variations in some stars. They were literally hundreds of years ahead of their time with some of their thinking and ideas. When I was Curator of Astronomy at the Yorkshire Museum in York, I christened these two as the Fathers of Variable Star Astronomy.

John Goodricke suggested that the two stars were eclipsing each other in a regular period causing the light variations. He was right and his ideas of objects eclipsing stars and causing changes of light in stars is still used today as astronomers use the same theory and principals to find planets orbiting other stars.

The eclipse occurs every 2.8 days and the magnitude varies between 2.2 – 3.5. 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 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. There does not appear to be a name for this star.

Epsilon also has a magnitude of 2.9 and like zeta does not appear to have a name. Epsilon is also a B class star, with a temperature of 26,000’C and is 640 light years away.

NGC 869 and NGC 884 both with a magnitude of 3.7 and 3.8 respectively form the famous double cluster. They mark the sword of Perseus These are open clusters with 350 and 300 stars respectively, lying about 7,600 light years away and about 300 light years apart.  They are both visible to the naked eye but seen through binoculars they are spectacular.  Each cluster contains over 300 blue, white super giant stars. They are about 7,500 light years away.

One of the most spectacular meteor showers of the year is the Perseids which can be seen around the 12^th/13^th of August each year. Usually around 80 meteors per hour can be seen. The meteors or shooting stars as some people call them are small grains of dust left behind by a comet as it travels around the Sun.  There are several important meteor showers throughout the year. The comet connected with the Perseid meteor shower is comet Swift – Tuttle. 

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.

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A little ramble through 19th century astronomy - Vulcan in 1876

 Nature November 16^th 1876

Search for Intra Mercurial Planet

American observatories have been very diligent in the search for the supposed inter mercurial planet, no less than nine having given their whole time to the search on October 2,3,10 and 11 viz, those of Dartmouth college, Harvard College, Cincinnati, Glasgow (Mo), Washington, Albany, the Coast Survey in San Francisco, Ann Arbor, and the Observatory of Dr Peters, besides others that have made no report.

It is exceedingly creditable to the United States that they contain so many observatories, many of them of national ones, in which astronomical observations are so diligently pursued. 

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A little ramble through the Astronomical register January 1863 - The Elchies Equatorial

In the number of the ‘Monthly Notices’ for November last, will be found a very interesting account of the great equatorial telescope by the late Mr A Ross, which was shown at the 1851 Exhibition.

It is the property of Mr Grant, of Elchies, Morayshire; - the focal length is 16 feet, and aperture 11 inches: the mounting on the German plan, is by Ransome & May, of Ipswich. The declination and polar axes are about 5 feet long and six inches in diameter; the circles are discs of gun metal, 30 inches in diameter and one inch thick. One portion of the stand consists of 1 tons of iron, the greatest quantity ever cast into a single piece for any astronomical instrument.

The climate of Great Britain very unfavourable to the performance of large telescopes of this character: in the ‘Monthly Notices’ of March 1oth 1854, Mr Grant gives two drawings of Mars, one which, taken with a five feet telescope in India, he says is “actually a little world”, - that taken with the great telescope described above is not nearly so distinct in details,- and he adds, “ I doubt whether the large glass would show it equally well, even were the weather favourable”.

Professor C P Smyth, who made several observations with the Elchies Equatorial last September says, “there were only two occasions during the week when I had the good fortune to witness, for a few minutes each time, a cessation of those atmospheric disturbances on the which the definition of stars seen in a good telescope so greatly depends.” This is but proof, that an instrument of moderate size is more generally useful in this country than one of excessive proportions.

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Cooke Telescope Tales - Cookes and the Mayflower 2

Scientific Instruments made by the York based company Cooke Troughton and Simms which was formed in 1922 were sent across the Atlantic Ocean on board the Mayflower 2.

 The Mayflower 2 sailed on April 20^th 1957 from Plymouth in Devon replicating the original voyage of the Mayflower in 1620. The Mayflower 2  arrived in Plymouth Massachusetts on June 22^nd 1957 and was then towed to New York City on July 1^st 1957.

 The instruments were placed in a treasure chest where when it arrived in New York City was greeted by President Eisenhower. It then became a tourist attraction with its treasures including the Cooke Troughton and Simms instruments being seen by tourists.

 The instruments which were inscribed to commemorate their method of transport will eventually be taken by the company’s representatives in the cities of Boston, Chicago, and the states of California and Colorado.

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A little ramble through Pegasus the Flying Horse

 The winged horse of Greek mythology, born from the blood of Medusa after she was slain by Perseus, who can be found nearby in the sky.

The most famous feature is the great square outlined by 4 stars. Strangely and for some unknown reason the top left-hand star of the square which used to be known as delta Pegasi has now been transferred to Andromeda where it has become alpha Andromedae.

To the Arab astronomers the square of Pegasus was known as Al Dalw or the Water Bucket

The great square which covers a large area and contains surprisingly few naked eye stars, look at the square you will do well to see a dozen stars.

Alpha or Markab which means Saddle is the bottom right-hand star of the square  its magnitude is 2.5 but is believed to be variable, it is an A class star with a temperature of 9,500’C and is 133 light years away.

Beta or Scheat which means Shoulder is the top right-hand star of the square it varies in brightness between magnitude 2.4-2.7. It is a red M class giant star with a temperature of 3,500’C. The star is 196 light years away.

Gamma or Algenib which means Wing or Side is the bottom left hand star of the square with a magnitude of 2.8, lying 390 light years away. It is a B class star with a temperature of 20,000’ C

Epsilon or Enif which means Nose is 690 light years away and we see it as at magnitude 2.4, it’s an orange K class supergiant star with a temperature of 3,500’C.

Eta or Matar which means Lucky Star of Rain has a magnitude of 2.9 lying 167 light years away. It is a G class giant star with a temperature of 4,700’C.

For a large constellation Pegasus contains few nebulae or clusters, the only object that will interest us is M15 an outstandingly bright globular cluster at magnitude 6.2 which can easily be seen through binoculars. M15 at 12 billion years old it is one of the oldest known. M15 is about 33,600 light years away and is about 175 light years in diameter and contains around 100,000 stars.

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A little ramble through 19th century astronomy - Mu Dorado

Nature November 2^nd 1876

Mu Doradus

This star, which was called a fifth magnitude by Lacaille at the end of 1751, and a sixth by Brisbane was observed by Moesta from February 1860 to January 1861 of 8.9m or 9m only.

Perhaps one of our southern readers will put upon record the actual magnitude of this star, the period of which as Moesta remarked would appear to be one of considerable length.

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