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On Sunday 11th July WAS had its annual working party at the observatory.

The old saying "many hands make light work" certainly rang true as on this sunny and hot Sunday morning ten members arrived, tools in hand, to help with the many tasks. Much was achieved! The furniture was removed from the observatory and the observatory was then thoroughly cleaned; the storage containers were emptied and cleaned out. Anything that hadn't seen the light of day for several months was taken up the tip, the weeds were pulled up; the nettles strimmed back and the hedge cut right back.

The committee would like to thank all those that turned up and generously donated their time to helping out - a good job all round.

Thank you.

This months’ lecture was given by Professor Stuart Malin on the topic of ‘Distance’.

The Professor commenced the lecture by informing us that there were three important aspects in Astronomy: Mass, Length and Time. However, Distance also as an important role. What was actually needed at that time was a define unit for measurement of length. It is reputed that the measurement of the yard originated in the time of Henry VIII and this was to be from his nose to the ends of his fingers on an outstretched arm! At this point, the Professor moved over to a bit of maths. He informed us that a Greek astronomer named Eratostenes, who flourished way back around 240 BCE, invented a method for locating the prime numbers between 1 and 120. By eliminating multiples of numbers, one would only need to pass through the numbers five times to end up with all the prime numbers.

Eratosthenes was also the first person to make a calculation of the circumference of the Earth. This came about while he was working in Alexandria, Egypt, where upon the day of the summer solstice he noted the angle of the shadow on the wall down a well. He had heard that much further down the south of Egypt at a city called Syene, (probably near today’s Aswan), that the well had no shadow at all on this date. By measuring the distance between the two places and taking into consideration the angle of the shadow at Alexandria, he managed to come up with a figure for the circumference of the Earth. Although we know today that the stadia was the measurement of length in that period, we do not know exactly how long a stadia was. Some 100 years later Hipparchus calculated the distance to the Moon by taking the principle of moonrise to moonset, having to take into account that he was not at the equator. Hipparchus also went on to measure the distance to the Sun by calculating the difference in the angle of the moon at half phase, from 90°.

Professor Malin continued by moving on to measurements more known to us today – the metre. Originally, a metre was to be 1/1,000,000 of the distance from the Pole to the Equator. This being a French idea, however, it was not exactly a bright idea at the time. To overcome this problem the French had a metal rod held in Paris, just as a temporarily measure. The length of this rod was eventually adopted permanently. The next person the Professor was to inform us of being Michaelson, who invented the interferometer, in order to measure distance by wavelength.

A General Roy, who lived in Hounslow, used another new invention by Ramsden called a theodolite which he made measurements by triangulation. He used this method to measure from Greenwich down to the South Coast. In order to progress further, Roy made arrangements with Cassini who was in France, to arrange for fires to be lit along the north coast of France, so that he could continue his measurements.

In 1948, this was measured again, only to find a small error had crept in. This actually turned out to be down to the fact that in 1948 they took the wrong Transit Circle to start their measurements from at Greenwich. Michaelson and Molley used the interferometer of a large distance by speed of the Earth to the ‘ether’ – taking into account the speed of the ‘ether’. In 1905 Einstein put forward the Special Theory of Relativity to try and explain all this. Other famous people throughout the past have contributed to try to solve this puzzle of distance. Although Kepler came up with the three Laws of planetary Motion, it did not have any scale. Our Edmond Halley, observed the Transit of Venus, along with many other astronomers from other countries in order to get the distance of the Earth from the Sun. This was done by taking timings of Ingress by the various groups situated at different latitudes on the Earth. He should get a difference which would aid him into making this calculation. However, it was upon observing the Transit of Venus did the astronomers discover that Venus also had an atmosphere.

This atmosphere created problems for the astronomers in order to get precise timings for the time of Ingress and as a result, the Earth – Sun distance had too many different results. The next person of note being James Bradley, who studied the star Gamma Draconis and in 1752 he managed to measure the apparent motion of this star. This is known as the Aberration of light – the apparent displacement of a star from its true position, caused by the movement of the Earth going around the Sun. Professor Malin continued by mentioning two people who had individually made a chart fo the stars which compared their Absolute magnitude with Spectral classification. The Absolute classification gave them the temperature and colour. The two people now both share their name for this work: Einar Hertzsprung and Henry Norris Russell. Their findings on this chart being that for most of the stars, the fell within boundaries of a broad line which ran from the top left to the bottom right of the chart.

As there still was not a concrete distance of the Earth to the Sun by the next time the set of two Transits of Venus occurred in 1874 and 1882, astronomers set out to try once again. However, the Transit of 1874 was not to prove fruitful at all, with too many differences. By the time 1882 came along, the distance had almost been settled by a David Gill who studied the planet Mars for many years and in particular its time of retrograding in our skies. From these observations an almost correct figure was used for the distance of the Earth – Sun. However, this still needed to be clarified and in 1931 the asteroid Eros made another pass of the Earth, it would approach to within 16 million miles of Earth. In order to check this all out a series of 14 observatories over 9 countries took part. The position of Eros was determined by each of them and after some 10 years, a value of the Earth –Sun distance was made. This was achieved as when Eros was close it had a large parallax which could be measured easily and accurate. The astronomers used the parallax method to determine the distances to the stars. However, this was only accurate for stars up to a distance of around 160 light years. Today, we have the satellite Hipparchus in orbit which is continuously making accurate measurements of the stars.

The Professor explained to the audience why E = mc² and carried out an analysis showing how it all worked out. (I think many were still left confused).

I believe that this evening’s talk by Professor Stuart Malin enlighten all those who attended as to what ‘distance’ means to everyone, let alone us astronomers. More so, in that the Professor explained how each person went about their particular task in order to overcome their quest for a specific distance.

May’s lecture saw the return of popular speaker, Jerry Workman. Jerry is an avid eclipse chaser and he had come to talk to us on his visit to China in 2009 to see the eclipse.

The eclipse was on the 22nd July 2009 and was a long one with a totality of 5 minutes and 40 seconds. Unfortunately the weather was not favourable and Jerry was only able to show us a few photographs when the cloud broke a little. He also showed us photographs of the dropping light levels resulting from the eclipse.

Jerry went on to describe his trip around China and he gave us an insight into this fascinating country. He showed many photographs including the Green Tea fields at Hangzou, the city of Shanghai and an excursion to see the Terracotta Warriors, Beijing and an excursion to the Great Wall and the Birds Nest stadium (famous from last years Olympics) and the highlight of his trip; a cruise along the Yangtze river on the “Blue Whale”. He we saw some lovely images of the limestone cliffs, the deep gorges, houses precariously perched half way up a cliff, the people and culture etc.

Jerry then went on to talk about the other eclipse trips that he had been on and again we were treated to some lovely photographs of the eclipses and the trips:

Iceland, an eclipse with a totality of 3 minutes and 30 seconds
Madrid, Spain in 2005. Totality of 4 minutes and 11 seconds
Cornwall, UK on 11th August 1999, which was completely clouded out.
Turkey in 2006, totality 3 minutes and 30 seconds and the Sun was very high at 66˚
And finally Siberia in August 2008. Totality 2 minutes and 20 seconds.

This proved to be an informative and interesting evening. It was nice to see the places that Jerry had visited as well as the eclipses themselves. Jerry has promised to return to WAS next year and give us a talk on his trip to see the eclipse in Polynesia and Easter Island, which we look forward to.

And….fancy eclipse chasing for yourself? Well the next good one and easy one for eclipse chasers to see will be in the USA on the 21st August 2017. Start planning now….and take a look at NASA for details on this eclipse and others.

Sarah

This months’ lecture was given by Professor Sean Ryan on the topic of: The Quantum Universe – it’s the small things that count.

We were informed of the properties of Light in that light comes in both waves and particles. The smallest particles relate to quantum physics. Professor Ryan mentioned that there were many scientists involved with this aspect but concentrated on three: Einstein, Broglie and Schroedinger.

Einstein said that there had to be a reality and needed it to be found. However, it has not been discovered as yet. The introduction of quantum physics came in order to try to answer many questions regarding the properties of light.

Professor Ryan moved on to talk about the Photo Electric Effect

            Atoms             -           Protons
            Nuclei              -           Photons
            Quarks             -           Leptons           -           Bosons

This led on to Wave Particle Duality. It was pointed out that all of the above have both wave and particle properties. We have all probably heard of the term – quantum leap. This was explained as being a step up of energy. Each time an electron leaps up a scale it gains energy. Likewise, when it goes down a scale, it loses energy.

In addition, we were informed that energy levels of atoms explain mission/absorption of light, which enables us to measure the composition of stars.

Next we moved on to the Uncertainty Principle. Wave equation only reveals probability or finding the particles in each region of space. For wave and particles cannot know the location and its momentum.

Following this Professor Ryan explained Quantum Tunnelling. This being particles which appear to have too little energy. In quantum physics, particles have particle duality.  Wave particles are not localised, but extend over a large range. The physicists are using an instrument called a Scanning Tunnelling Microscope in order to scan the surface to aid their search.

The next part of this talk moved on to the generation of fusion in stars and the Sun.
Particles lack kinetic energy to overcome mutual repulsion. The distance of the closest approach  ≈400 radius of the proton. The Broglie wavelength being ≈200 the radius.
Professor Ryan showed us a demonstration of wave tunnelling and pointed out that we do not know which side the electron could be on, until we look for it.

The knowledgeable characteristics of a particle is summarised by its quantum numbers.

Finally we move on to the Exclusion Principle, which relates to discrete energy levels for electrons in atoms. These are important features in astronomy. Here Professor Ryan discussed the minimum mass limits for stars. A gas cloud contracts, so the density and temperature increases and stars eventually form. The stars burn hydrogen into helium.
In this scenario, as the gas contracts, particles become so close together that they are only one Broglie wavelength apart. Quantum wavelength properties become dormant.

However, in the case of compact stars, in dense matter, particle separation reduced to the Broglie wavelength so quantum properties dominate. The Exclusion Principle limits size - stars become too small to ignite and end up as brown dwarfs.  More massive white dwarfs have a smaller radius. Its close mass to 1.4 solar mass with a radius close to zero. The mass of the white dwarf builds up to the critical limit and the star goes supernova.

Or in laymans terms:

When the hydrogen is exhausted and cannot burn into helium, the star contracts, due to the hydrogen conversion process continuing, so the star contracts. The reason of contraction is due to no heat being generated. As the star contracts, the mass increases. Quantum physics kicks in as wave patterns develop, due to fewer particles.           

Kelvin          

On Wednesday March 17th thirty seven members and visitors received an interesting and informative talk from Mr Martin Hardcastle of the university of Hertfordshire.

Martin's talk, titled Enormous Energies – Particles from Space, centred around cosmic rays; what they are and where they are from. Cosmic rays, radio active particles, were first discovered by Victor Hess in 1912. The lower energy cosmic rays are generated from supernovae – a slow motion explosion that can last for thousands of years. During this time the particles are accelerated away from the supernova and into space. It is now known that the highest energy cosmic rays cannot be generated from supernovae explosions but from outside the Milky Way, deep in space. The source of these high energy particles are likely to be radio emissions from Radio Galaxies.

Martin then went on to discuss radio galaxies in more detail and in particular Centaurus A which is the nearest radio galaxy to us – some 10million light years away. Cen. A is not a typical elliptical radio galaxy and was described as being rather “messy”. Lots of monitoring of Cen. A in both radio waves and X-Rays has demonstrated that it has a jet that is moving at half the speed of light. The X-Ray observations have shown us where in the jet the cosmic ray particle acceleration is occurring.

Martin finished his talk by saying that we were only beginning to scratch the surface of cosmic rays and that though they have been around for a century the source of the particles and properties of the particles are still a big mystery. The talk generated lots of interesting questions from the audience, which was followed by the draw of the raffle.

This meeting was also the first opportunity to use the new PA system recently purchased by the society. This made a big difference to the quality of the lecture making sure that all could hear our speaker nice and clearly.

Sarah

February’s meeting featured  a lecture from Dr Dan Andrews of the Open University, titled Ptolemy – Landing on and Sniffing a comet.

Dan started off by discussing what comets are – essentially balls of frozen ice (of water, carbon monoxide and dioxide and ammonia) and other materials that are moving through space in elliptical orbits around the Sun. Comets were formed at the beginning of the solar system outside of 20AU. These proto-comets were moved to their current location by the actions of planetary migration which then went on to form the Kuiper Belt.

Dan then went on to discuss how comets are studied and this included ground based observations, though these are hindered by our atmosphere, and from space, with spacecraft that allow you to approach the comet and study it in much more detail.

Deep Impact was then mentioned – this fired a copper “bullet” into the nucleus of comet Temple 1 and some stunning images were shown of this collision.

Rosetta was the next mission talked about. Launched on the 2nd March 2004 it is due to land on its target comet, 67P/Churyumov-Gerasimenko in August 2014. This comet is a typical small Jupiter family comet, which orbits the sun in 7 years. It was discovered in 1969. Rosetta is a combined orbiter and lander both parts of which will be the first to orbit and land on a comet. Ptolemy, part of this set-up, is an Evolved Gas Analyser and Dan brought this along for us to see. Weighing in at 4.1kgs it was tiny in comparison to its lab equivalents where whole rooms are full of equipment for measuring just one type of gas.

Dan went on to talk about the fact that Ptolemy will be able to tell us the chemical composition of comets, how organic materials form, their comparison with meteorites, temperatures at which chemical reactions take place and much more.

Rosetta is a £1,000,000,000 mission with everything on the spacecraft being controlled from the ground. The Deep Space Network of antenna communicates with Rosetta, which is currently being turned on twice a year.

In Summary of the lecture Dan talked about comets being an essential area of study and that by gaining a full understanding of the chemistry and history of comets we could be able to tell how life on Earth started.

This was an interesting and informative lecture that generated lots of questions from the audience.

Sarah

Subject:   Types of Telescopes – Advantages and Disadvantages.

Our Practical Evening was held at 8pm in the Frankie Vaughan Studio at Woodrow, and twenty four members and visitors attended.   It was decided at a previous Committee Evening that the format for these evenings should be changed from being led by one person, (usually Chris Rowland), to a discussion group which involves members.  We are now fortunate to have a larger group than previously, and many of the members have knowledge and experience of the subjects being discussed, and are happy to pass this information on.

The telescope discussion evening had been brought forward by a month at the request of several members, and proved to be very interesting.

A number of telescopes were on display, including the new donated Celestron 102 SLT, the Meade ETX90 Maksutov, and the Tasco ‘scope, all of which are available for members to use if requested.  Other members brought along their own telescopes, including a Celestron 130 SLT reflector, Celestron 8” and 9.25” Schmidt Cassegrains, a Celestron 8” SE, a Williams Optics 80mm refractor, and a Celestron 8” SCT on a German Equatorial Mount.  Each member gave a brief talk about their particular telescope, which gave us an idea of the different specifications, and the advantages and disadvantages of each ‘scope.

Also on display was the Celestron Sky Scout, a very useful piece of equipment for finding your way around the sky.  Several members have now bought this.

Jackie Harris showed us her back-pack (a large camera bag) into which she is able to very neatly fit all her equipment for travelling, including her Williams Optics 66mm telescope, eyepieces, filters and GOTO handset.

The discussion also touched on various aspects of astro-imaging, although this will be a subject at a future meeting. We look forward to more Practical Evenings in this format. 

Tea and Coffee was available.

Our trip to see the Aurora
February 26th – March 2nd  2009
Jackie Harris & Sarah Whittaker

We  travelled with Hurtigruten flying from Heathrow to Oslo then on to Tromso where we joined the Norwegian Postal Boat - Ms Trollfjord on an Astronomy cruise with Dr John Mason, the principal lecturer at the South Downs Planetarium in Chichester.

Our  Route:
Tromso – Honningsvag ( North Cape) - Kirkenes
Honningsvag - Hammerfest – Tromso.

All of the ports of call were special in their own way and we learnt about the indigenous Sami people, the reindeer migrations and the effects of the second world war. We were absolutely delighted to hear, on the first night, the on board radio broadcast that there was an Aurora to be seen on deck.  Needless to say we soon abandoned any idea of dressing for dinner and we learnt to be prepared to put on our arctic gear at very short notice!!

Sarah took some excellent photos of the Aurora over three separate nights and to my delight and Sarah’s embarrassment  John Mason used them as part of his lectures whilst we were on board.
The final piece de resistance was on our last morning when we went dog sledding.  The light was fantastic and we saw altocumulus lenticularis cloud formations and fabulous snow covered landscapes as we raced along in wooden sleighs lined with reindeer skins pulled by a team of 8 wonderful dogs!

WAS annual BBQ and Perseid viewing evening.

We saw two! Honestly we did, we actually saw two of the Perseid Meteors. Quite amazing really considering it was 99.9% cloud cover.

We actually had a very nice evening, yes it was cloudy but it was also pleasantly warm (which was a tremendous improvement on last year, as if you remember, the weather was horrendous). A campfire was started and the BBQ’s lit. About 10 members came along and a variety of sausages and burgers were cooked and enjoyed. We then proceeded to lie back on the benches by the campfire and look up. Once in a while the clouds would part and a star could be seen. Then as fast as it had appeared it disappeared. Someone must have been on our side though that evening because at about 10pm a small opening appeared just where we needed to be looking and within the space of about 10 minutes we had seen two. The opening then closed up!

It was also nice to welcome Oliver and his father, two potential new members who had come along in the hope of spotting a meteor or two. It was nice to be able to show them the WAS observatory and talk to a child who was obviously very keen and interested in astronomy, especially the planets.

All in all it was a nice evening. Lets hope that next years annual BBQ and Perseid viewing will have better weather still.

Sarah

Images by Jan

Solar Observing evening on the 2nd July at Woodrow.

We had a good evening, and got to see the sun with a small prominence at the 6 o'clock position through the WAS Solarscope. Some members brought their scopes with them, and after the sun went down we turned our attention to the moon, which was a bit misty through feint cloud but a very dark orangey colour. I have also enclosed a photo of the moon which I took with my little Panasonic Lumix camera.

Jan Dell

Practical Evening report

The WAS Practical evenings which take place on the second Thursday of each month in the Frankie Vaughan Suite at 8pm give members a chance to find out more about various aspects of astronomy from simple subjects such as “How to read a Star Map and learn about the night sky,” to more complicated subjects such as “Imaging with a Webcam, CCD Imager or DSLR camera.”

The meeting on 7th May 2009 dealt with the latter, and was given by Chris Rowland as a Powerpoint presentation. Chris talked about each method of imaging and its advantages and disadvantages, and showed us examples of these cameras.

During the session members asked questions, and added the experiences gained with their own equipment.

Our thanks to Chris for an enjoyable and informative evening.

These evenings are a valuable way of learning more, and keeping the interest in our hobby alive, so why not come along and see what happens.

A list of the Practical Evening dates and subjects, can be found in the Calendar section of the website

Jan Dell

To see the beginning of time by Andrew Lound

Our monthly lecture on Wednesday 20th May 2009 was given by Mr. Andrew Lound, whose lectures are very interesting, informative and always amusing. This was one of his many Odyssey Class Dramatic Lectures titled “To see the beginning of Time” Forty four members and friends attended the evening.

His presentation started with the human obsession of always looking into the past, and why structures such as Stonehenge were built for alignment of the heavens. He talked about Tycho Brahe and his observatory, Gallilleo and William Herschel and their discoveries, and how telescopes were invented, and were first used for navigation and terrestrial purposes by these ancient astronomers.

Andrew showed us a picture of Christiaan Huygens in period dress, and (dressed in ruffle and cloak himself ) said that it was appropriate dress, and that all astronomers should dress that way, which provoked amusement amongst members.

The first ground based telescopes were reflectors with huge focal lengths, in some cases 200 ft. long. The invention of the refractor with the addition of an accurate mirror reduced these to a short focal length, and they became much smaller in size.

The Paris and Greenwich Observatories and Admiralty House played an important part in navigation, and in the First World War telescopes were used by troops, along with binoculars for aerial reconnaissance. Dolland patented the telescope in 1758 and observations improved. Since this time there have been books, films, radio plays, and cultural developments on astronomy and the telescope.

One of the more important aspects of astronomy today is light pollution, and large optical telescopes have been built on mountains across the world to avoid this. Thanks to huge advances in technology, even children have access to these facilities via computer links.

Andrew talked at length about the massive contribution that the Hubble Space Telescope has made to the exploration of planets, stars, galaxies and the universe in general, and its discoveries of dark matter and black holes. He then talked us through some amazing images that the telescope has produced, saying that Hubble has brought us back to reality and allowed us to “drink with our eyes.”

Are there other civilisations and cultures who have looked at us and no longer exist? It is believed that 13.7 billion years is not the beginning of time, and that the new James Webb Space Telescope which will replace Hubble in 2014 will look even deeper into space. Andrew finished his talk by saying that we should never feel inferior in the universe, we are part of it, and we will always be passionate “To see the beginning of time.”

Paul thanked Andrew for a great lecture. We look forward to his next lecture at our IYA event on the 3rd October 2009.

Galaxy Zoo - Chris Lintott

Jerry Workman Wednesday 18th February

Jan Dell

Robotic telescopes 19th Novemer 2008

An unexpected change to the scheduled lecture evening on Wednesday 19th November gave Wycombe Astronomical Society an opportunity to learn about the many Robotic Astronomical Telescopes around the world.

Dr. Ulrich Kolb from the Department of Physics and Astronomy at the Open University came to tell us about his involvement with some of these telescopes, and to link up with one of them on the internet.

These telescopes are called RATS or Robotic Astronomical Telescopes. They are used for research purposes and long term student studies.There are three projects in the U.K. involving the Universities of Leicester, Bradford and the Liverpool John Moores University. The RATS used by these universities are situated on mountain tops in the Canary Islands, and have involvement from other countries throughout Europe.

The Liverpool telescope is situated 2,400 metres above sea level on the island of La Palma and is involved in the Swift mission that discovered Gamma Ray Bursts. It is supported by PPARC and the Astronomy Research Council, making 40% of the observing time available to astronomers in the U.K.

The Bradford Robotic Telescope is on Mount Teide in Tenerife, and is available for schools to use.

The Leicester Telescope called PIRATE (the Physics Innovations Robotic Astronomical Telescope) is located at the Observatori Astronomic de Mallorca (OAM), and is the host institution of the Open University residential school course Observing the Universe (SXR208) in Observational Astronomy and Planetary Science.

Dr. Kolb explained the various ways in which these telescopes can be accessed both remotely and in queue and live modes with interactive sessions from the general public. He then went on to provide us with a live internet link-up with PIRATE, and we were actually able to see the telescope inside the dome and how it was operated by him from a laptop. We were hoping to be able to set the ‘scope to do some actual observing, but the area was cloudy, so this was not possible. However he showed us how to use the software using a previously stored image.

Finally he set out his vision for the future, where Robotic Astronomical Telescopes worldwide would be linked by one communication system.

We thanked him for a very interesting and informative lecture which sparked questions from members. We hope to hear more about his work in the future.

A raffle was held and refreshments were available.

Perseid Barbeque 12th August

Fifteen intrepid members and family (9 for the BBQ with the remainder arriving later) braved the weather to meet at Woodrow for the Perseid Barbeque - unfortunately it was a bit wet!!

However the weather cleared by about 10pm and a number of Perseids were spotted by some. The observatory was opened with good views of Jupiter with several moons in an unusual configuration. Views - through the bushes - of M13, Albeiro and the Moon. Several had their cameras set up on tripods to photograph the Moon and Jupiter in close proximity.

Thursday 7th August

WAS was also able to show those persons present its new purchase of a solar scope and it is hoped that we will be able to loan this out to members on a regular basis for observing. Chris has been able to obtain a tripod through work and this has provided a really steady mount for the scope.

Jackie also discussed the need to have a working party in order to cut back the bushes surrounding the observatory and it was great to get such a positive response to this. Sunday the 31st of August is the date that has been set aside (weather permitting) and all members are welcome to help with this task

It was nice to see a good turn out for the practical evening and with our new found knowledge we hope that the weather will be kind for us next Tuesday (12th) for the annual WAS BBQ and meteor hunt.

Sarah

Wednesday 16th July

On Wednesday 16th July Wycombe Astronomical Society saw the welcomed return of popular speaker Dr. Stuart Clark. Titled “Do we need a new theory of gravity” Stuart gave WAS an informative lecture.

Stuart started by talking about Isaac Newton’s theory of gravity (1687) and then on to Albert Einstein’s general relativity (1915). Moving on, Johannes Kepler’s was the first to say that if the Earth was moved from the centre of the universe and the Sun was placed in the centre instead then there had to be some force to keep the planets in line. Kepler looked at the motion of the planets and came up with the three laws of planetary motion i.e. that all planets orbit in ellipses with the Sun at one focus of each ellipse, that the speed of a planet changes as it orbits the Sun, implying that a planet moves more slowly when it is furthest from the Sun and the third law relates to the times taken for a planet to orbit the Sun to distances. These laws are what Newton used to “work out” gravity i.e. he codified the force called gravity. Newton never tried to explain what gravity actually was.

With this, future events i.e. comets could be predicted however, movement of other bodies within the universe were not obeying Newton’s rules of gravity. Uranus did not follow the rulebook and it was discovered that it was being pulled of course by another body; Neptune.

Stuart then went on to explain that the launch of the spacecraft, Pioneers 10 and 11, were the first to be sent to the outer solar system. NASA decided to use these to search for other planets. Both craft were very sensitive to motion and they detected a tiny force, 10 billion times weaker that Earth’s gravity. With research and data collected from the archives they have been able to explain part of the Pioneer Anomaly; that there are four possibilities for direction of force and two types of mass.

Stuart then talked about where we are up to currently and that there is three modified theories on gravity. Now would be a good time to find a modern explanation for gravity and, if found, this would be the most exciting discovery to date.

Several questions were asked at the end of Stuart’s talk which rounded off an informative and enjoyable evening.

Sarah

Wednesday 18th June

Mr. Martin Lunn - M.B.E. (for services to astronomy and education) was the guest speaker at our monthly lecture evening on Wednesday 18 th June in the Sports Hall at Woodrow High House, which was well attended.

His lecture titled “Pre-Telescope Astronomy” commenced with the building of Stonehenge three and a half thousand years ago which is thought to have fulfilled both astronomical and religious functions. We were told the reasons why moons were given different names, i.e. Harvest, Hunters, Sturgeon, Lenten and Blue moons.

Early civilisations gave us Calendars of the world, which were set by the Sun and Moon and measured the day, month and year, and with the stars and constellations were used by farmers for planting and harvesting crops. We heard how the Babylonians gave us a 24 hour clock with 60 minutes to one hour, and how 12 gods gave 12 months to a year. Their original Calendar was 354 days long. Following that came the Julian Calendar, which was in use until the 20 th Century, and has been superseded by the Gregorian Calendar today.

Martin also mentioned various early astronomers such as the Babylonians, Greeks, Egyptians, Arabs, Aborigines and Koreans etc., and their early beliefs and contributions to astronomy. He also talked about the first predicted solar eclipse by Thales a Greek philosopher in 585BC.

The intervention of the Church and writings in the monasteries in the middle ages changed peoples’ ideas. The monks wrote their diaries in red ink, hence the expression a “Red Letter Day”.

Martin talked about famous astronomers such as Aristotle, Ptolemy, Hipparchus, Copernicus (who confirmed that the sun was the centre of the Solar System), Kepler (famous for his laws of planetary motion), Tycho Brahe (who witnessed Supernova 1572 in that year, and also saw the Great Comet of 1577), and Gallileo who looked at the heavens through a telescope in 1609 and discovered the four Galilean moons of Jupiter. These new ideas about the universe, and the use of the first optical telescopes changed the course of astronomy forever.

Martin then went on to talk about Viking Astronomy, which is of particular interest to him, although he said it is a very difficult area to research, and was ongoing. He had given a lecture on the Vikings at the Viking Festival in York, where he is Assistant Curator of Astronomy at the York Museum.

Paul Millington thanked Martin for a very enjoyable and informative lecture.

A raffle was held, and refreshments were available.

Jan Dell

Wednesday 11th June

In 1958 the 13 acre site was designated suitable for the observatory and at 7000 feet altitude and a perfect, arid climate it was easy to see why. Kit Peak has the largest collection of telescopes in the world – 23 telescopes on the same site.

Steven went through the major telescopes with us, giving details of what each one was used for. The McMath-Pierce 1.5m scope is a solar telescope. The Mayall 4m scope, which was built in 1972, is used for the study of dark matter and this is the most prominent telescope on the site. The newest telescope is the 3.5m WIYN telescope is the most optically refined ‘scope.

The Kit Peak observatory has made some important science discoveries including galaxy rotation curves, high redshift galaxies and the distance scales.

Steven then went on to discuss the opportunities that visitors have at Kit Peak. They have nightly stargazing programs, overnight stargazing programs and advanced observing programs. With all of these there is a hands on approach. Guests can have a go at visual observing, CCD imaging, webcam and DSLR imaging.

Finally Steven showed us his astro “set up” in his backyard and some of the stunning photographs that he had been able to achieve with his equipment were amazing.

A big thank you must go to Steven for contacting WAS and offering to give us a talk on his work. This was an informative and enjoyable extra evening.
Sarah

The following links take you the various sites devoted to Kitt Peak (all links open in new windows):
The Observatory
The Visitor Centre/Outreach
National Solar Observatory
Mountain Information
MDM Observatory

Wednesday 16th April

In my last report recently I stated that Wycombe Astronomical Society had been treated to two excellent talks, now we can make that three.

On Wednesday 16th April Jocelyn Bell Burnell came to WAS and gave a talk titled “In pursuit of Pulsars”.

We started off by listening to an audio recording of a Pulsar (a pulsating radio star), which was pulsating at 660revs/minute. This sounded a bit like a rough running car engine.

Jocelyn then gave a run down on the birth/ life and death of stars and where pulsars fitted into this system.

All stars are born in dark areas of a galaxy. These areas are rich in molecules and dust particles, which become concentrated, and increase in gravity. The increased gravity pulls in more particles, which raise its mass and gravity again, this increase pulls in more particles and so the sequence continues. The temperature of this star gets hotter and hotter and when it reaches 10 million Kelvin nuclear reactions start in its core, and the star begins to shine. This nuclear reaction is called nuclear fusion, during which hydrogen is changed to helium and the extra energy produced by this reaction is light. Our Sun, a “typical” star currently half way through its life cycle, “burns” 600 million tonnes of hydrogen per second.

At this point in her talk envelopes were handed out with a small slip of paper in them. This simply read “in picking up this piece of paper you have used a million times more energy than a radio telescope receives from all the known pulsars in a year”. A fact that I find difficult to comprehend!

We also had a demonstration of a “pulsar”. Using her kitchen timer tied to a piece of string, Jocelyn spun this around her head. We could all detect the warbling sound of the pulses as it went round and round, and as she spun it faster the pitch of the sound changed.

In summary, Jocelyn mentioned the names of modern items that have been called pulsars such as a Nissan car, a geranium flower, and pulsar watches, the latter being an appropriate name, as pulsars are excellent timekeepers. However the watch company had not heard of the historical name, and tried to sue the radio astronomers in the United States! This made us all chuckle.

This was an excellent talk and Jocelyn was a very good speaker who is obviously passionate about her subject. Some forty members and guests attended the talk and showed their appreciation at the end with some excellent questions and answers.

Sarah

Wycombe Astronomical Society has recently been treated to two excellent talks. (April and March)

April 3rd - Practical Evening

At Aprils practical evening we were given an excellent talk by WAS member Stefan Zietara.

Stefan’s talk was all about eyepieces. Prior to his talk Stefan had posted a set of questions on the WAS forum asking all members to volunteer information about the types of ‘scope that we own, what type of eyepieces we have or would like to have etc., and this information was used during his talk.

It started with a video, set to music by the band “Take That” showing that there are simply hundreds of eyepieces available to choose from. Stefan then went on to talk about the history of early eyepieces with slides showing the different types and designs, and how they had evolved from these early ones into the more advanced varieties available today.

He told us that planetary observation and widefield and deep sky observing require different sizes and types of eyepieces, and advised how we can best build up a good collection of eyepieces to suit our observing needs.

There were many different types of eyepieces on display for all to have a look at and discuss, including Stefan’s own “Holy hand grenade” – a huge Nagler eyepiece. At the end of the talk Stefan presented WAS member, Sandy Giles with a book. Sandy won the competition question, posted on the forum, to give a name to his new eyepiece – “Naglarsaurus Rex” or N.Rex for short! Jan Dell won second prize with her name of “Cosmic Canonball”.

It was apparent that Stefan had put a huge amount of effort into assembling his talk together as an excellent Powerpoint presentation, and it was appreciated by all the members that attended. Thanks Stefan very much for a most enjoyable and informative evening!

March 19th

March’s main lecture saw the welcomed return of popular speaker and astrophotographer Nik Syzmanek.

We were in the sports hall at Woodrow for this lecture which was just as well as about 60 members and guests attended; an excellent turnout!

Nik’s lecture was an updated version of the previous one that he had given to us but it had lost none of its appeal. He showed us many beautiful photographs, which were all taken by a variety of different methods. The emphasis of his talk was very much for us all to try astro-photography and see what results we could achieve. There was some humour added into the lecture as well, like the photographs of the anatomically correct snowmen, taken when a planned visit was hindered by bad weather rendering photography impossible.

The lecture finished with an eight minute video, set to the music of Chaldean Crossing by The Enid, showing a variety of astrophotographs and scenery at La Palma in the Canary Islands.

Sarah

SPA Meeting

On Saturday 23rd February Woodrow High House and Wycombe Astronomy Society hosted the first beginners “starting out in astronomy” course, organised by the Society of Popular Astronomy.

The event was deemed to be a great success. Over 90 tickets were purchased before the day and several more tickets were sold on the day. It was a jam-packed meeting with several lectures on various topics of astronomy from the different types of telescopes available, finding your way around the night sky to observing the Moon and Sun and more distant objects.

The meeting, held in the sports hall at Woodrow, had an SPA stand where books / CD’s / sweatshirts etc could be purchased, a display for Wycombe Astronomical Society and David Hinds telescopes also had a display of various telescopes / the new Celestron “skyscout” / binoculars etc. They were also on hand to offer advice to potential new ‘scope owners.

During the lunch hour Chris opened up the WAS observatory for all the guests attending the lectures to have a look and this generated much interest in our society.

All in all it was a very successful day for the SPA and for WAS as we were able to welcome some new members to our society.

Sarah

Telescope Evening

We had planned to hold this event in the Sports Hall, but with the benefit of a clear sky we decided to do some observing. The area around the Observatory was waterlogged from heavy rain, so we set up our telescopes in the Woodrow Car Park.

Thirty-eight members and potential members attended, and objects viewed included the Moon, M42, M45, the Auriga clusters and Mars, as well as others of interest.

Our Society is thriving and has enrolled a number of new members recently, who have made contact via our website, and come along to our monthly Practical Evenings. Our Telescope Evening is a great way to help people who are new to Astronomy and are keen to learn more about this absorbing and fascinating hobby.

An informative and enjoyable evening was had by all who attended.

Jan Dell

The 2007 Christmas Party

Sarah Whittaker our Publicity Officer compiled an excellent Quiz consisting of seven picture boards for us to identify the following categories:- Constellations, Famous Astronomers/Scientists, Planetary Satellites, Famous Observatories, Messier Objects (by number and common name), Solar Features/Phenomena, and the hardest category of all on Lunar Features. We were divided into five teams of four people. There was a possible 72 marks on offer. The winning team achieved marks in the 60s’, and each received a prize.

Our thanks to Sarah for such an interesting and challenging Quiz and to Committee members for making it such an enjoyable social evening.

Jan

Coping with Dew

November’s practical astronomy evening was “Coping with dew” and Chris gave a talk to 22 WAS members on this subject. Starting with a definition of what dew is and why it occurs Chris then went on to talk about methods of preventing it. The most effective method is to start by using a dew shield and this can be either a proprietary one, or a home made one made out of a black camping mat and some Velcro to hold it in place.

Other methods included the use of dew heaters that keep the tube of the telescope marginally warmer than the ambient temperature and a hair dryer, used to produce a gentle warm breeze onto the corrector plate to reduce dew.

Afterwards we were able to get out and do some observing as the weather was clear. The main focus of attention was comet 17/P Holmes, which many members were able to see through the ‘scope for the first time. We were also able to take a look at Mars, although it was still too low on the horizon to get really decent views. The society’s green laser pointer was put to good use pointing out the comet and constellations such as Aquarius, Perseus, the Square of Pegasus, Delphinius etc and objects such as the Andromeda galaxy.

It was nice to see so many people at the practical evening and for the societies facilities to be put to good use.

Sarah

Observing Comet 17P/ Holmes

For those of you who have been following the forum recently you will have noticed that it has got quite busy; in particular there is a thread on Comet Holmes.

This comet started off as an insignificant “star” (we cannot see a the tail as it is behind the comet - because we are between the comet and the sun), however Holmes decided to explode a few days ago and is now a magnitude –2.5 and a nice object to track down in the evenings. It is easily visible with the naked eye and looks lovely through a pair of binoculars.

On Wednesday evening (30 th October) eight WAS members got together at the observatory to take a look at comet Holmes. Binoculars and the societies ‘scope were used and some imaging carried out using a CCD camera was done as well. We will look forward to seeing these in the image gallery.

If you want to track down comet Holmes for yourself go to www.spaceweather.com where you will find a link to a map showing its position……its worth a look! Sarah

Annual General Meeting 2007

On Wednesday the 17th of October the WAS annual general meeting was held. Attendance was very good this year with some 40 or so old and new members coming along.

The meeting went very well. Paul Millington gave a good account of the previous year and thanked the committee and individual members for their work involved in the running of the society.

We also had reports from Chris Rowland and Kelvin Stephens with regards to the observatory and finances. This was followed by an auditors report from Nick Presney.

The success of the practical astronomy evenings were discussed and a request was put to the audience for future subjects.

The election of officers stands the same with no changes in the current positions.

Perhaps the best thing about the evening was that it was nice and clear. So following on from the meeting and a cup of tea and biscuits we were able to do some practical observing. At one point there were, I think, some 16 members crammed around the telescope in the observatory!

Birth and Death of Stars

On Wednesday the 19th of September WAS saw the return of popular speaker Barry Kellet. Originally titled the life and death of stars Barry then changed this to the birth and death of stars and the process from beginning to end was discussed.

The first part of the lecture was used to talk about entropy. Barry asked his audience to “bear with him” while he discussed the process and after some explaining it became clearer as to what entropy had to do with star birth. Essentially entropy is a measure of disorder or chaos. Where gravity pulls things in entropy pulls things out. Barry discussed the process of molecular cloud collapse and entropy in this role, protostar formation, proton chain reactions, nutrinos, white dwarf deaths and much more besides.

This was the first time Barry had presented this talk, using a presentation borrowed from a colleague. Although challenging to the audience at times, the subject material proved to be very interesting and was delivered by Barry in an informative and interesting presentation.

Sarah Whittaker

Designs of craft were presented to the audience and considerations were made for power and propulsion, protection from radiation, thermal control, protection from dust particles and communication.

One of the ways Davids’ craft was to be powered was by Antimatter: sub atomic particles (atoms, electrons and neutrons) which, when they come into with other atomic material, annihilate it, producing pure energy as a result. This was an interesting concept. Already small quantities of antimatter energy are being produced at the CERN organisation for nuclear research. 1mm diameter of anti hydrogen is equivalent to 2 tons of TNT.….think what one could achieve with larger quantities!

Davids talk to us on a journey, first to Mars and back – travelling at under the speed of light – then onto an outer planet and finally onto a class A star. All of these journeys could be achieved within the crews life time!

This was an excellent talk by David and it was very evident that a lot of time, effort and research had gone into it.
Thank you.
Sarah

Visit to Greenwich - click here to see a report by Sarah Whittaker on the visit to the Greenwich Observatory.

On Wednesday 16th of May approximately 40 members of WAS enjoyed another very informative and highly entertaining talk by Andrew Lound from The Planetary Society.

Titled ‘Lord of the Rings’ Andrew’s talk charted the history of observing Saturn and its rings and Moons from the 17th century through to the present day.

A number of astronomers including Galileo, Christopher Wren, William Herschel, Cassini and Huygens have all observed the planet and published papers and books on various aspects of Saturn and its rings. The discovery of Moons and white spots, and the appearance of the planet at different times of the year and at different periods of its orbit were all attributed to these astronomers.

Andrew then went on to talk about the various space probes that have been used to observe the planet. Pioneer II was the first to ‘fly’ past Saturn. Voyagers I and II were next to make observations and the photographs taken during this mission were outstanding. Details, including colour and structure of the rings could be seen. They were able to see through Saturn’s atmosphere to its surface and observe violent storms raging and ribbons of weather patterns moving over its surface. The probes discovered the outer F ring, which showed that its structure was braided and twisted, and was accompanied by two shepherding Moons. Following the Voyager probes the Hubble Space telescope has taken further amazing pictures of the planet and its rings and Moons.

The Cassini probe being the most recent, was sent to Saturn via a sling shot around Venus and the Earth then onto Jupiter and finally reached the planet in 2004. Lightening was discovered in the upper atmosphere, violent rotating storms were seen which lasted for weeks. Storms appeared around the polar regions and appeared to have direct weather correlations to those on Earth. A bizarre hexagonal structure was seen around the South Pole and material was being removed from the outer F ring by the effect of gravity from its two shepherding Moons as they moved around the ring and changed their positions.

Finally Andrew showed many images of Saturn’s various Moons, including Titan its largest moon, showing their structures and compositions. Titan showed high altitude clouds, dynamic weather systems and seasons. Radar examination of its surface showed lakes of hydrocarbons, volcanoes of ice and mountains, and that the surface is young and changing.

Andrew captivated his audience for an hour and twenty minutes. The photographs that he showed were stunning and the music, sound effects and costume he wore all made for an excellent presentation.

Click on image above to see larger version

At the other end of the field many members set up their telescopes (approx 10 in total), binoculars and cameras on tripods. The society’s observatory was also opened up and this gave the opportunity for some of the newer members and friends to observe Saturn for the first time whilst waiting for totality.

The eclipse started at approximately 20.20 pm and it wasn’t long before a ‘bite’ taken out of the moon, in the bottom left corner could be seen. By 11pm totality had been reached and the moon turned a beautiful coppery red colour. At this point cameras were clicking rapidly as many photographs were being taken! At around 11.30pm most members were beginning to get cold and the group began to disperse.

Thanks must be given to Alistair who helped many members with their photography techniques, whilst trying to take his own photos, and to Chris who was wandering around with a hair dryer on a 100 ft extension cable. He was carefully drying everybody’s optics, as scopes, cameras and binoculars had started to dew up.

Thanks also go to Jan and Sarah for providing the jacket potatoes. It was agreed that an excellent evening was had by all.

Members from Wycombe Astronomical Society and five visitors met in the Sports Hall at Woodrow High House on Wednesday 17 th January for the annual Telescope Evening, at which members set up their various pieces of astronomical equipment in the form of telescopes and tripods, cameras, webcams, and binoculars for discussion with other members. A variety of telescopes were on display, ranging from 80mm to 11” including reflectors, refractors and Schmidt Cassegrains, showing both equatorial and alt. azimuth mounts. Of particular interest was a home made wooden equatorial wedge that one of our members made on which to mount his Celestron 11” telescope. This was set up with a webcam, and a deep sky imager which he had constructed from a “job lot” of pieces that he had bought. The whole set-up was very impressive, and apparently worked very well.

Click on either image to see a larger version

The five visitors that came showed keen interest, and were encouraged by members to come to our Practical evenings once a month to find out more about the Society and what it offers.

Tea and coffee was available, and a raffle was held. The evening finished at about 10pm. No observing was possible that evening due to a cloudy sky.

Meeting of 15th November 2006
Bob Lambourne of the Open University gave a most interesting talk on the Expanding Universe.

He started with a review of the history of Hubble's discoveries about the scale of the universe and that the greater the distance a galaxy is from us the greater the red shift.

He tied this in with the cosmologies proposed by Einstein and De Sitter which also suggested that the Universe could be expanding. Later work by Friedmann, Robertson and Walker (FRW) produced a variety of possible universe descriptions, depending on parameters such as the density, ratios of matter to energy and the Hubble constant.

Recent work using type 1a Supernovae have showed that the expansion rate of the universe was initially reducing, as expected, but about a billion years ago the slow down stopped and now the expansion is accelerating.

Now it got really weird because Bob showed that distant objects with high redshifts could be receding faster than light. How can we see them? Will the light ever get to us? What happens is that as the light moves through space in our direction the recession speed slows down and the light can move to an area where the expansion speed is less than the speed of light. The light can then reach us - eventually. Bob finished by showing us space-time diagrams allowing for the expansion and its changes. They show the light cone as a tear drop with areas where objects are receding faster than light but can be observed but there are also areas which can never be observed. This is a very mathematical subject and could easily have been totally baffling but Bob was able to put it across in a very clear way so that even without the maths you could come away with an impression of what was going on and an understanding of the excitement of these discoveries of what is really out there!

Geminid Meteors
The Society organized an evening for its members to get together and observe the annual Geminid Meteor Shower on Friday 15th December, however, the skies were cloudy on the day (100% cover), and the event was postponed until the following Saturday evening.

Unfortunately, being a Saturday many members had other arrangements, but ten members met at the Observatory at 8pm, and enjoyed hot homemade soup and French bread, whilst waiting for the Meteors to show.

When they did appear, the number of meteors observed was disappointing with only about half a dozen, spread over an hour or so. During the evening, the Observatory 10” Meade Schmidt Cassegrain scope was set up, and several members bought their own scopes and binoculars. One member bought his parallelogram and mounted his large binoculars on it for us all to try out. It gave an excellent and impressive result. Objects observed during the evening were the Moon, Saturn, M45 The Pleiades, and Messier objects in Andromeda, among others.

The sky was very clear, and the air cold, and ideal for observing. We finished observing at around midnight, and a good social evening was had by all those attending

Society visit to Herstmonceux

The society trip to on the 30th September was a great success despite the low turnout of Society members. Sadly September was a bumper month for astro fairs, star parties and conventions making it difficult to attend everything, however we spent a very interesting day touring the exhibits, attending lectures and trying not to be too tempted by the goods on the stands!!

We were fascinated by Nik Szymanek's lecture on Astrophotography and came out convinced that with the right filters we could get some great images too! Dr Bob Fosbury of ESA also told us about the successes of the Hubble telescope and how it has widened our knowledge. In between we tried out all the hands on exhibits and visited the various domes with their antique telescopes. All in all a very enjoyable day out.

Fig 1


Fig 2


Fig 3

Fig 4

Click on any of the images above to see a larger version

Observations of Delta Cephei

Chris Rowland, Jan Dell, Sarah Whittaker, John Fifield

Members of the Wycombe Astronomical Society made observations of the magnitude of the star Delta Cephei to determine its period and so its distance using the period-luminosity law for Cepheid variables.

Data Collection

Delta Cephei is a naked eye star in the Constellation Cephus. Its magnitude varies regularly over a period of a few days and there are two convenient comparison stars nearby. WAS members made a total of 116 observations from June 2005 to February 2006, giving magnitudes from 3.4 to 4.3. We made measurements using naked eye or binoculars. When measurements were made independently by several observers at the same time the magnitude estimates were within 0.1m or 0.2m of each other. The poor weather and light pollution made Delta Cephei difficult to see sometimes and on some occasions the fainter comparison star was not visible. This will make the fainter observations less reliable. The raw measurements are shown here; there is no obvious pattern to the data. See fig 1

The data was analysed using the Anova method and a plot of the period shows a clear peak with a period of 5.3691 days - see fig 2

A plot of the data at this period gives a clear indication of the light curve - see fig 3

This shows the characteristic Cepheid "shark's fin" light curve with a rapid rise followed by a slow decline. This is the official light curve - see fig 4

The main difference seen in our data is that the amplitude is less than expected, especially at the low magnitude end. This could be due to a tendency to overestimate the magnitude when the star was only just visible.

Determining the distance to Delta Cephei

The absolute magnitude of a Cepheid variable is given by the function

M = -2.76 log(P) - 1.4

Where M is the absolute magnitude and P is the period in days.

For our measurement of the period this gives an absolute magnitude of -3.41; in other words if Delta Cephei was at a distance of 10 Parsecs (32.6 light years) it would have a magnitude of -3.41 and so be the brightest object in the night sky, except the Moon and sometimes Venus.

The formula:

m = M + 5 * Log(D) - 5
relates the apparent magnitude - m, the absolute magnitude - M and the distance in parsecs - D.

The average magnitude from our measurements was 3.92. This gives a distance to Delta Cephei of 294 Parsecs, or 958 Light years.

Comparison with Official values

The period of Delta Cephei is 5.366 days; our measurement is within 50 seconds of this. The average magnitude is actually 4.07m, our measurement is slightly higher, possibly because of a tendency to overestimate the brightness when the star is only just visible. The distance to Delta Cephei has been measured by the Hubble space telescope using parallax as 891 light years. Our measurement is within 10% of that, almost entirely because our mean magnitude is less than the actual value. This was an interesting and educational exercise, and we learned a lot about taking and recording observations.

Chris Rowland