Astrognome Scrapbook August 17th 1958

Lunar Probe Able 1

The first attempt by America to send a probe to the Moon, Able 1 ended in failure. After just 77 seconds when Able 1 was 12 miles high the lower stage of the rocket exploded destroying the probe. It would not be until Ranger 7 in 1964 that the Americans successfully launched a Moon mission.

In those days the Americans were well behind the Russian who had already sent probes to the Moon by 1959.

All these early missions were unmanned.

Astrognome Scrapbook August 14th 733 Solar Eclipse

Solar Eclipse 733 AD

The weather today is pretty miserable with lots of rain however on this day in 733 the weather must have been much better because an eclipse of the Sun was seen from England.

The Anglo Saxon chronicle tells us that on this day King Ethelbald of Mercia, which covers the modern day area of the midlands in England captured the manor at Somerton which is in south Somerset and all the disc of the Sun was like a black shield.

The eclipse was also seen in Europe, the Chronik der Seuchen tells us that "one year after the Arabs had been pushed back across the Pyrenees after the Battle of Tours the Sun was so diminished as to excite universal terror"

The eclipse was an annular eclipse and at maximum only 2.5% of the Sun was showing. An annular eclipse occurs when although the Moon is directly in front of the Sun it is a little bit further away from the Earth meaning it appears slightly smaller and therefore cannot block out all of the Sun. The tern Annular comes from the Latin Annulus meaning 'Ring'.

Astrognome Scrapbook August 13th 1596 Omicron Ceti 'Mira'

Mira the Wonderful Star

Mira

I often refer to John Goodricke and Edward Pigott of York as being the ‘Fathers of Variable Star Astronomy’ which they are, but the first variable star to be discovered was found nearly 200 years before them.

The Dutch astronomer David Fabricius saw a star in the constellation of Cetus the Whale he recorded it of being of the third magnitude, which means it is quite easy to be seen with the naked eye, this was of course was in the days before the telescope had been invented. A few weeks later he could not find it!

In 1603 the German astronomer Johann Bayer who was producing his Uranometria star atlas recorded it slightly fainter at the fourth magnitude and gave it the Greek Omicron. Bayer allotted the brightest star in each constellation the Greek letter alpha followed by beta the next brightest star  and so on until omega. We still use this system today.

It then vanished again, it was not until 1638 that the Dutch astronomer Johann Holwarda recognised that the star omicron ceti became bright every 331 or so days. Sometimes it can become as bright as  Polaris the North Star while at its faintest it drops sown to the ninth magnitude and is a test to find it in binoculars.

Omicron Ceti is the prototype star for a large class of these so called long period variable stars. These are large red giant stars approaching the end of their lives.

This was the first time astronomers had seen a star change in brightness and they were amazed.  They called omicron ceti, Mira which means “The Wonderful Star”. 

Astrognome Astronomy Perseid Meteor Shower

The Perseids

I observed the Perseids last night Aug 12th/13th and saw 81 meteors between 11.15 pm and 03.45 am. There were some fantastically bright meteors. I don't have a camera so I can't show you any pictures of the ones I saw.

There did appear to be some confusion when the night of maximum would occur and a few days running up to the maximum various press reports were saying that you could see the Perseids, It is true there would have been a few meteors either side of maximum but the night of 12th/13th was the night with the best chance of seeing the Perseids.

Astrognome Astronomy Perseid Meteor Shower

Perseid Meteor Shower

On the night of August 12th/13th the Earth will pass through the stream of dust left by a comet, we will see lots of shooting stars or meteors. This is the Perseid Meteor shower.

Shooting stars have nothing at all to do with stars they are tiny grains of dust, which burn up as they enter the Earth's atmosphere. They can be seen on any clear night of the year. However when the Earth passes through a stream of material left by a comet we see lots of meteors this is a meteor shower.

The Perseid meteors are so called because they all appear to come from the constellation of Perseus. This  meteor shower is connected with comet Swift Tuttle, it was discovered in 1862. The comet was approaches the Earth every 130 years and was last close to the Earth in 1992 , it will return again in 2125.

comet swift tuttle in 1992

It is possible to see meteors a few days either side of Aug 12/13 but this is when most meteors will be seen. If you look up into the sky after 11.00 pm you will be unlucky not to see at least one Perseid. They only for a fraction of a second so you have to be quick, you can look in any direction, Perseids are usually bright and white in colour.

The Perseid meteor shower has a long history, having first been recorded by the Chinese in 36 AD.

 In 258 AD, a Christian called Lawrence promised the Roman emperor Valerian all the wealth of the Empire. Valerian thought he meant gold and silver, while Lawrence meant that the poor and sick people of the Empire were its wealth. Valerian took a dim view of this and had Lawrence roasted alive. The following night the Perseids came through exactly on schedule and people who saw this believed these were tears from heaven. Later Lawrence was made a Saint; hence the old name for the Perseids was ‘The Tears of St Lawrence’.   

In 1535 the French explorer Jacques Cartier was exploring the land we now call Canada. In August of that year he arrived at a very large river. The Perseids were coming through as usual, and as Cartier knew the story, he called the river after St Lawrence.

Jacques Cartier

Good Luck with your meteor watching!!

Astrognome Scrapbook August 10th 1080 Bright Comet

Comet of 1080.

At present in the sky is comet  C/2014 Q1 PanSTARRS, it is low in the sky and most easily seen by people in the southern hemisphere. It is a spectacular sight in binoculars showing 3 tails. The comet at the moment is passing through the constellations of Crater and Hydra

However 935 years another comet was also observable in the same part of the sky. Discovered by the Chinese astronomers  on August 10th 1080 this comet which was discovered just south of Coma Berenices passed through Crater and Hydra. It was visible for 36 days. The two comets do have different paths.

The 1080 comet  was not visible as long as C/2014 Q1 but was almost certainly brighter.

Astrognome Scrapbook August 6th 1809 birth of Lord Tennyson and Astronomy

Lord Tennyson Aug 6th 1809- Oct 6th 1892

Alfred Tennyson, 1st Baron Tennyson was born on August 6th 1809. He would go on to become Poet Laureate during much of the reign of Queen Victoria. He is one of the most popular of British poets.

He also had an interest in astronomy!

Astronomy was a significant and positive muse for Tennyson that enabled him to explore questions of faith, doubt and immortality.  In his ‘Locksley Hall’ (1837-8), Tennyson describes his own experience of astronomical observation. He tells the reader how ‘Many a night from yonder ivied casement, ere I went to rest / Did I look on great Orion sloping slowly to the West’. He also writes ‘Many a night I saw the Pleiads, rising through the mellow shade.

He also owned  a small telescope that he used to look at the night sky. He knew many well known astronomers including Charles Pritchard, Savilian professor of Astronomy at Oxford University and Norman Lockyer who built a solar observatory, discovered Helium and was the first editor of the Nature magazine.