Castle Point Astronomy Club
1969-2019 - 50th Anniversary Year
Castle Point Astronomy Club Diary
December 2018 by Dave Stratton
Castle Point Astronomy Club


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Wednesday 5th December 2018

Andrew said that next week we have Peter with a talk on Astro Imaging for Beginners and the week after it will be our Christmas Social.

Peter said that a Geminid Meteor watch was planned for Thursday and Friday at our dark sites depending on the weather – possibly both.

He added that Comet Wirtanen was currently mag 5 and a good object for bins.

Andrew introduced Martine for this evening´'s talk: Explorers of the Night Skies (Martine Hales and Others)

Martine said that this evening was a joint effort to demonstrate that even a short talk could easily make a good event providing we got together. She added that the various ‘Explorers ’ were presented in chronological order.

She introduced Jim for his contribution on Robert Hooke.

Relatively little is known about Robert Hooke´s life. He was born on July 18, 1635, at Freshwater on the Isle of Wight the son of a churchman. He was educated by his father John.

At one time he was simultaneously the curator of experiments of the Royal Society a member of its council, Gresham Professor of Geometry and Surveyor to the City of London after the Great Fire of London (in which capacity he appears to have performed more than half of all the surveys after the fire). He was also an important architect of his time – though few of his buildings now survive and some of those are generally misattributed – and was instrumental in devising a set of planning controls for London whose influence remains today. Allan Chapman has characterised him as ‘England's Leonardo ‘.

Hooke studied at Wadham College Oxford during the Protectorate where he became one of a tightly knit group of ardent Royalists led by John Wilkins. Here he was employed as an assistant to Thomas Willis and to Robert Boyle for whom he built the vacuum pumps used in Boyle´s gas law experiments. He built some of the earliest Gregorian telescopes and observed the rotations of Mars and Jupiter. In 1665 he inspired the use of microscopes for scientific exploration with his book, Micrographia. Based on his microscopic observations of fossils, Hooke was an early proponent of biological evolution. He investigated the phenomenon of refraction, deducing the wave theory of light and was the first to suggest that matter expands when heated and that air is made of small particles separated by relatively large distances.

He performed pioneering work in the field of surveying and map-making and was involved in the work that led to the first modern plan-form map, though his plan for London on a grid system was rejected in favour of rebuilding along the existing routes. He also came near to an experimental proof that gravity follows an inverse square law, and hypothesised that such a relation governs the motions of the planets, an idea which was independently developed by Isaac Newton. Much of Hooke's scientific work was conducted in his capacity as curator of experiments of the Royal Society a post he held from 1662 or as part of the household of Robert Boyle.

Sadly we have no pictures of the man and he was not given credit for his work with Newton on his Principia.

Martine introduced Andrew for: Sir Isaac Newton.

Isaac Newton was born at Woolsthorpe near Grantham in Lincolnshire, England on 4 January 1643 (New calendar) or 25th December 1642 (Old Calendar). His father died before he was born and in 1645 his mother married a clergyman from North Welham in Leicestershire. She went to live with him while Isaac Newton lived with his grandmother. His mother returned to Woolsthorpe in 1656 when her second husband died and Isaac Newton went to live with her again.

From the age of 12 to 14 Isaac Newton went to Grantham Grammar School. During this time he lodged with an apothecary and his family. Then in 1659 Isaac had to leave to help his mother on the family farm. Isaac was not in the slightest bit interested in running a farm and in 1660 he went to the grammar school again. In 1661 he went to Trinity College Cambridge. He obtained a BA in 1665. In 1666 – he had to flee Cambridge because of an outbreak of the plague and he returned temporarily to Woolsthorpe. He returned to university in 1667.

In 1667 he was elected a fellow of Trinity College. The same year he was elected a member of the Royal Society. In February 1672 a paper he wrote about light and colours was read to the society. In 1669 Isaac Newton became Lucasian professor of mathematics. In the meantime, in 1668, he invented a reflecting telescope.

In 1689-1690 Isaac Newton was MP for Cambridge University (in those days Cambridge University had its own MPs). He became an MP again in 1701-1702, but he did not take an active part in politics.

Isaac Newton published his masterpiece Principia Mathematica in 1687. It set out his theory of gravity and his laws of motion.

In 1695 Isaac Newton was made Ward of the mint and in 1699 Master of the mint. He resigned his fellowship and professorship at Cambridge in 1701.

In 1703 he became president of the Royal Society. He was knighted in 1705. Meanwhile in 1704 he published another great work about light.

Isaac Newton died at the age of 84 on 20 March 1727.

Martine introduced Gord for his Explorer - the unluckiest astronomer ever.

Gord told the story below in his own inimitable style but I have extracted the detail from the internet.

Guillaume Joseph Hyacinthe Jean-Baptiste Le Gentil de la Galaisière born 12 September 1725 – died 22 October 1792 was a French astronomer who discovered several nebulae and was appointed to the Royal Academy of Sciences.

He was part of the international collaborative project organized by Mikhail Lomonosov to measure the distance to the Sun, by observing the transit of Venus at different points on the Earth. Edmond Halley had suggested the idea, but it required careful measurements from different places on earth, and the project was launched with more than a hundred observers dispatched to different parts of the globe, for observing the transit coming up in 1761. The French expedition turned out to be particularly unlucky, and perhaps the most unfortunate was Guillaume Le Gentil, who set out for Pondicherry, a French possession in India. He set out from Paris in March 1760 and reached Isle de France (now Mauritius) in July. However, the Seven Years´ War had broken out between France and Britain in the meantime, hindering further passage east. He finally managed to gain passage on a frigate that was bound for India's Coromandel Coast; he sailed in March 1761 with the intention of observing the transit from Pondicherry.

Even though the transit was only a few months away, on 6 June, he was assured that they would make it in time. The ship was blown off-course by unfavourable winds and spent five weeks at sea. By the time it finally got close to Pondicherry, the captain learned that the British had occupied the city, so the frigate was obliged to return to Isle de France. When 6 June came the sky was clear, but the ship was still at sea, and he could not take astronomical observations with the vessel rolling about. After having come this far, he thought he might as well await the next transit of Venus, which would come in another eight years (they are relatively infrequent, occurring in pairs 8 years apart, but each such pair is separated from the previous and next pairs by more than a century.)

After spending some time mapping the eastern coast of Madagascar, he decided to record the 1769 transit from Manila in the Philippines. Encountering hostility from the Spanish authorities there he headed back to Pondicherry, which had been restored to France by peace treaty in 1763, where he arrived in March 1768. He built a small observatory and waited patiently. At last, the day in question (4 June 1769) arrived, but although the mornings in the preceding month had all been lovely, on this day the sky became overcast and Le Gentil saw nothing. The misfortune drove him to the brink of insanity, but at last he recovered enough strength to return to France.

The return trip was first delayed by dysentery and further when his ship was caught in a storm and dropped him off at Lie Bourbon (Réunion), where he had to wait until a Spanish ship took him home. He finally arrived in Paris in October 1771 having been away for eleven years, only to find that he had been declared legally dead and been replaced in the Royal Academy of Sciences. His wife had remarried, and all his relatives had ‘enthusiastically plundered his estate ’. Due to shipwrecks and wartime attacks on ships, none of the letters he had sent to the Academy or to his relatives had reached their destinations. Lengthy litigation and the intervention of the king were ultimately required before he recovered his seat in the academy, remarried, and lived apparently happily for another 21 years.

Martine said her own explorer was James Clark Maxwell.

James Clerk Maxwell FRS FRSE (13 June 1831 – 5 November 1879) was a Scottish scientist in the field of mathematical physics. His most notable achievement was to formulate the classical theory of electromagnetic radiation, bringing together for the first time electricity, magnetism and light as different manifestations of the same phenomenon. Maxwell´s equations for electromagnetism have been called the ‘second great unification in physics ’ after the first one realised by Isaac Newton.

With the publication of "A Dynamical Theory of the Electromagnetic Field" in 1865, Maxwell demonstrated that electric and magnetic fields travel through space as waves moving at the speed of light. Maxwell proposed that light is an undulation in the same medium that is the cause of electric and magnetic phenomena. The unification of light and electrical phenomena led to the prediction of the existence of radio waves.

Maxwell helped develop the Maxwell–Boltzmann distribution, a statistical means of describing aspects of the kinetic theory of gases. He is also known for presenting the first durable colour photograph in 1861 and for his foundational work on analysing the rigidity of rod-and-joint frameworks (trusses) like those in many bridges.

His discoveries helped usher in the era of modern physics, laying the foundation for such fields as special relativity and quantum mechanics. Many physicists regard Maxwell as the 19th-century scientist having the greatest influence on 20th-century physics. His contributions to the science are considered by many to be of the same magnitude as those of Isaac Newton and Albert Einstein. In the millennium poll – a survey of the 100 most prominent physicists – Maxwell was voted the third greatest physicist of all time behind only Newton and Einstein. On the centenary of Maxwell's birthday, Einstein described Maxwell´s work as the ‘most profound and the most fruitful that physics has experienced since the time of Newton’.

Martine introduced Paul for his explorer George Lemaître.

Georges Henri Joseph Édouard Lemaître, RAS Associate (17 July 1894 – 20 June 1966) was a Belgian Roman Catholic priest, astronomer and professor of physics at the Catholic University of Leuven. He proposed on theoretical grounds that the universe is expanding, which was observationally confirmed soon afterwards by Edwin Hubble. He was the first to derive what is now known as Hubble´s law, or the Hubble-Lemaître law and made the first estimation of what is now called the Hubble constant, which he published in 1927, two years before Hubble's article. Lemaître also proposed what became known as the ‘Big Bang theory ’ of the creation of the universe. The term ‘Big Bang’ was coined by Fred Hoyle rather sarcastically as he didn´t believe it at all and was in favour of the steady-state view.

Martine introduced Andy T for his Explorer Fred Hoyle.

Sir Fred Hoyle FRS (24 June 1915 – 20 August 2001) was a British astronomer who formulated the theory of stellar nucleosynthesis. He also held controversial stances on other scientific matters—in particular his rejection of the ‘Big Bang ’ theory, a term coined by him on BBC radio and his promotion of panspermia as the origin of life on Earth.

Andy said that he had a problem choosing which aspect of his life to tell us about – he chose his work with radar.

British radar was well established at the start of WW2 in fact all our ships after 1935 were equipped with it. Fred realised that there was a weakness in that the height of incoming aircraft was not indicated. He set out to resolve this issue. He found that the existing data produced contained enough info to calculate the height of the targets. His first attempt worked, but was too slow a second attempt was good enough to give our pilots before they took off so they could plan their attack better. He was also put in charge of countermeasures against the radar guided guns found on the Graf Spee. Britain´s radar project employed more personnel than the Manhattan project.He saved many lives.

What a lot we got.

Wednesday 12th December 2018

Andrew said that next week we have our Christmas Social.

He also said that although the programme for next year is taking shape he still needs slots filling.

Jim reminded us that he has a lot of scopes available.

Ed said that next week there are two meteor watches planned for the Geminids.

Mike introduced Peter for his talk: Astro Imaging for Beginners

Peter mentioned that his career was in construction with no scientific background. However now he is involved with the BAA and he just loves comets. He has been actively interested since his schooldays.

He said that in recent times there have been major advances in technology – mobiles and tablets with cameras and cameras themselves were changing fast with the bridge, mirrrorless and the DSLR.

He treated us to a very nice image of Venus and Mercury taken with a mobile he said that a convenient tree in this image added to the interest – so think about the composition.

We also saw several great images of the Moon, halos and even Jupiter all with a mobile that was placed at the eyepiece of a scope. He added that there were many apps available – many free – to enhance the photographic abilities of the mobile, he showed a screen-full of them.

However the best was a DSLR or a mirrorless which is more compact as it does not have a mirror and therefore the eyepiece cannot see through the lens it uses a screen on the back. It should be cheaper but isn´t! When used in conjunction with Registax etc they can give excellent results.

We saw a pic of a Canon with a selection of lens and attachments or of course the camera can be attached directly to the scope instead of an eyepiece.

He showed us a splendid image of M31 which was a stack of six 180second exposures the image is 30 across i.e. 6 Moon diameters.

Peter said the camera was generally used in manual mode so that shutter speeds from a few seconds and on, aperture/f number, the ISO/sensitivity and the focusing.

Other necessary kit included a tripod and a ball head so the camera can be positioned correctly. He said the f stop was usually set wide open for maximum light gain, ISO was set high but not normally to max as modern cameras often had extremely high ranges 800 to 1600 was typically good.

He said that focus can be difficult and has to be done manually – later cameras have ‘live view’ which helps focusing there are several aids to achieve focus available.

We saw a nice image of a crescent Moon with Mercury and the Pleiades. Plus a very unusual aurora image taken in Essex. Also a star trail image around the pole that took 22 5 minute images.

Peter said there were a few gadgets to mount a camera on and track stars he mentioned the AstroTrac, Sky Watcher and Vixen Polamic.

Peter showed us a 180 second image of the Milky Way taken at Kelling Heath which was excellent and then another taken from his garden with a 60second image it was not great but after processing it became not bad at all. He said that filters can help overcome some pollution.

He recommended that cameras were set to take RAW images and not JPEG as this ensured all the data was gathered.

He said that Deep Sky Stacker was free also Paint.net there were loads of others but not all free. GIMP is some image processing software similar to PhotoShop but free.

We saw several of his own images including the Pleiades, the Orion Sword region and the Rosette Nebula. He finished with Comet 46P Wirtanen.

Great.

Wednesday 19th December 2018

Our Christmas Social is here again – doesn’t time fly?

It was thoroughly enjoyed by a reasonable attendance of members.

This time it was organised by Mary who has assisted Ted and Eileen for eight years, but this time was very much in charge. There were contributions from Gord and Betty.

Seasonal Greetings to All!

Wednesday 26th December 2018

Boxing Day - No meeting


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