WADHURST ASTRONOMICAL SOCIETY

JANUARY NEWSLETTER 2008

INDEX: MEETINGS, OTHER NEWS, CONTACTS

MEETINGS

A Very Merry Christmas to all Members and a Great New Year

COMMITTEE MEETING

Members of the Committee are respectfully reminded that there will be a meeting on Monday the 7th of January 2008 at the Abergavenny Arms, Frant starting at 1930.

As always, any full member of the Society is very welcome to join us.

DECEMBER MEETING

Being the Christmas meeting, members were welcomed with coffee and mince pies on a very cold night.  The mince pies having survived the journey up the stairs and passed the Weight Watcher's meeting below.

Why Are We Here (Still)

Talk by Paul Treadaway at the Society's meeting on Wednesday 12th December

Paul is a member of the Society and he began his talk by saying that it was due to very many circumstances that human beings are here at all and that there are many other considerations to explain why we are STILL here!

Einstein's formula for the relation between energy and mass is e = mc²  and shows that matter conversion produces vast amounts of energy.  To illustrate this, just 1 gram of pure fissionable material was employed in the atom bomb that destroyed Hiroshima in 1945.

The Big Bang occurred 13.7 billion years ago and it is believed that there was about a billion times more matter than there is now although the reason for this imbalance is not yet known.

Following the first three minutes after the Big Bang there was a period known as Nucleosynthesis, which lasted for the next 17 minutes during which time the light element of hydrogen and some helium atoms emerged but no heavier stable elements appeared.

The elements that make up the human body were not around then so we could not possibly have existed that early.

The heavy elements came about during star explosions known as Supernovas.

We were shown an image of M98 taken in 1998 when a bright and energetic supernova was discovered at a distance of 11.2 parsecs from Earth.  The supernova was visible for only a very short time, but to demonstrate how a supernova develops Paul referred to the Veil Nebula, which is the remnant of a supernova that occurred some 30,000 years ago.

During several cycles of supernovas heavier and heavier elements are produced resulting in the elements found today in the Periodic Table.

The Sun is made of the remnants of past supernovae and here on Earth we stand on solid matter, - another reason we are here.

About half of all stars are in fact binary pairs, which would make like on planets orbiting around them very unstable.  The Sun is a single star; another reason why we are still here!

A star's luminosity also depends on its mass.  If the Sun were twice the mass it is today, it would have 16 times the luminosity.  Also if the Sun was just 2.3 times its mass, its life would be reduced from its predicted 5 billion years to only 0.86 billion years.  Life on Earth would, in any case, become intolerable well before the end of our Sun's life.

Another threat to human life is the presence of asteroids, which may be the remnants of planets that might have collided.  Then Paul mentioned that Pluto might well be a rocky planetoid that is a captured comet.  At least the Earth is relatively stable - at present.

This could not be said of Venus, which is very hot with a tilt of 177o and a very acidic atmosphere.  Jupiter and Saturn each have huge gravity that helps them mop up much the debris in space.

Next for consideration was our Moon.  The Moon's rocks match those of the Earth indicating that it had its origins on the Earth.

The Earth owes much of its stability to the influence of the Moon and also it is responsible for the tides, without which life might not have emerged from the seas.

Water is very important to us but has some unusual properties.  Hydrogen combines with many elements but its combination with oxygen is very strong forming water and this is difficult to break.  Water is dense enough to gouge out rock and has very many properties essential to human life.

We rely on energy from the Sun, which has a staggering output of 386 billion billion megawatts of which the Earth receives 1.3 Kw/m².  There is also 0.6 watts/m² at the Earth's surface from fission in its interior.

Our atmosphere is controlled by gas emitted from volcanoes, although it can also cause disastrous results at times of eruptions.  Paul talked of an eruption that took place in 1783 on Iceland that caused the death of 9,000 people not because they were gassed or enveloped in material from the eruption but because of starvation due to sulphuric acid in the atmosphere causing a failure of crops and a consequent lack of food.  Many Europeans also died of starvation at this time.

Paul concluded his talk by tabling the threats to life on Earth.  He referred to the Sun's evolution and eventually becoming a Red Giant.  The threat from asteroids, comets and material from the Oort cloud and Kuiper Belt presented a never-ending danger.  Then came volcanoes and Climate Change.

All together, we are very lucky to be here at all but we are also constantly under threat of annihilation.

Paul's talk generated considerable of interested discussion but the general conclusion was that we should go over to the pub as quickly as possible!

JANUARY MEETING

Wednesday 16th January 2008  Phil Berry talks about "The Strasburg Astronomical Clock". The talk will be followed by the Society's Annual General Meeting.

There will also be a "Help List" at the meeting.  Anyone, whohas any suggestions, queries or requests for help, can use this list t seek help; then we can see if any other member can help.  There is plenty of time before the next meeting and it might be something others are having trouble with but haven't thought of bringing up.

The meeting begins at 1930 although members are invited to arrive anytime after 1900.  This is a good time to exchange ideas and discuss problems.

The venue as always is in the Upper Room of the Methodist Church at the east end of Wadhurst High Street, opposite Uplands College.

FUTURE MEETINGS & EVENTS

Wednesday 20th February 2008 John Vale-Taylor will be talking to Tim Bance, an amateur astronomer with a host of experience in astronomy and telescope building.  "The Tim Bance Interview".

Wednesday 19th March 2008 A welcome return of Konrad Malin-Smith with his talk "The Magellanic Clouds".  This takes us just outside our own galaxy to two of the Milky Way's closest neighbours in space.

Wednesday 16th April 2008 Greg Smye-Rumsby gives a talk he has entitled "Bits and Bobs".

Wednesday 21st May 2008  Our own Brian Mills, who contributes the excellent Sky Notes each month is giving a talk about Occultations.

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OTHER NEWS & INFORMATION

A visit to Phil Berry's Observatory

Following the December meeting, Brian Mill's and I cheekily asked if Phil Berry would invite us back to see the observatory he has been working on for the past few months.

It was a very clear evening but bitterly cold and frost on the ground was thick underfoot as we were taken across Phil's lawn towards the silhouette of his newly built observatory.  As we approached the dome, the first of his security features sent beams of red light across the frost-covered lawn.

Inside was a dehumidifier and also a heater to stop the humidifier freezing up, but then we saw something to make any amateur astronomer's mouth water.

In the centre of the observatory was an 80 mm Williams Optics Fluorite Triplex refracting telescope on a Vixen GDPX equatorial mount which itself was secured to a concrete base kept separate from the observatory and its floor.

Also on the mount, Phil uses an 80 mm Skywatcher refracting telescope as a large finder-scope.

The CCD camera Phil uses is the Starlight Express SXV/H9 monochrome camera with a remote controlled filter wheel.

All this was linked to equipment mounted on a crowded trolley also built by Phil, using a laptop computer to control imaging and nearly everything else.

The dome itself rotated in a perimeter groove on top of the walls on a set of soft-rimmed wheels so that the dome moved with relative ease.  Phil even talked about having it motorised at some time in the future.

The aperture slid back revealing a gap of just over half of the dome's roof leaving a very useful view of the sky.  The sliding part of this aperture was prevented from hitting the backstop hard by incorporating a modification that included springs to prevent any sudden vibration.

Tracking of the scope could be kept to within pixel accuracy and focussing could be done very finely indeed using "Robo-Focus".

All moving parts of the dome had been left open on the observatory as it had been delivered but again Phil had taken great care to completely seal them in.

In case of a mains supply failure, essential equipment would be kept running for up to an hour using a USP.

Very very impressive.

SKY NOTES FOR DECEMBER

Planets

Mercury is an evening object at magnitude -0.5, setting around 11/2 hours after the sun. It will be best seen during the second half of the month but even then it will not be easy to locate.

Venus at magnitude -4.0 is still a brilliant beacon in the morning skies and cannot be mistaken for anything else. At the end of the month it still rises 2 hours before the sun with its phase becoming more gibbous.

Mars is very obvious on the Gemini/Taurus borders due to its colour and also its magnitude of -1.6. During January its brightness will diminish as it moves further away from the Earth. This will have been the best opposition of Mars until 2016.

Jupiter at magnitude -1.9 may just be visible low on the south east horizon in the morning skies, rising around an hour before the sun at the end of the month.

Saturn lies in the constellation of Leo (the lion) at magnitude 0.6. The rings are still becoming more "edge on" as seen from earth which means they reflect less sunlight and so the planet is fainter. Around the middle of the month Saturn will rise at around 20.00hrs GMT.

Lunar Occultations

Meteors

From the 1st to the 6th of January, the Quadrantid meteor shower will be active with the maximum occurring on the 4th at 06.00. This shower has a very brief maximum when rates can reach around 100 meteors per hour. The radiant, which lies between the tail of Ursa Major and northern Boötes, is actually circumpolar from these latitudes although in the early/late evening it is very low in the sky.

Comets

At the time of writing this Comet 17/P Holmes is still a naked eye object in Perseus and was easily found by some of us after the December meeting.

ISS

Unfortunately almost all passes of the ISS this month occur in the early morning. Details of visibility can be found at www.heavens-above.com 

Advance warning

21st February sees a total lunar eclipse lasting from 01.43 to 05.09.  Totality lasts from 03.00 until 03.51.

Reminder

As I mentioned in the last newsletter, there will be a grazing occultation of a 6th magnitude star on 14th March which will be visible from our part of Kent. It occurs on a Friday evening at 21.43hrs and will require anyone who is interested and has a portable telescope to assemble at a yet to be determined location. Please let me know if you may be interested.

Brian Mills  01732 832691     BRIAN@wkrcc.co.uk

NASA SPACE PLACE

Ultraviolet Surprise

by Patrick L. Barry and Tony Phillips

How would you like to visit a universe full of exotic stars and weird galaxies the likes of which astronomers on Earth have never seen before?

Now you can.  Just point your web browser to: galex.stsci.edu and start exploring.

That's the address of the Galaxy Evolution Explorer image archive, a survey of the whole sky at ultraviolet wavelengths that can't be seen from the ground. Earth's atmosphere blocks far-ultraviolet light, so the only way to see the ultraviolet sky is by using a space telescope such as NASA's Galaxy Evolution Explorer.

About 65% of the images from the all-sky survey haven't been closely examined by astronomers yet, so there are plenty of surprises waiting to be uncovered.

"The Galaxy Evolution Explorer produces so much data that, beyond basic quality control, we just don't have time to look at it all," says Mark Seibert, an astronomy postdoc at the Observatories of the Carnegie Institution of Washington in Pasadena, California.

This fresh view of the sky has already revealed striking and unexpected features of familiar celestial objects. Mira is a good example. Occasionally visible to the naked eye, Mira is a pulsating star monitored carefully by astronomers for more than 400 years. Yet until Galaxy Evolution Explorer recently examined Mira, no one would have guessed its secret: Mira possesses a comet-like tail 13 light-years long.

"Mira shows us that even well-observed stars can surprise us if we look at them in a different way and at different frequencies," Seibert says.

Another example: In April, scientists announced that galaxies such as NGC 1512 have giant ultraviolet spiral arms extending three times farther out into space than the arms that can be seen by visible-light telescopes.  It would be like looking at your pet dog through an ultraviolet telescope and discovering his ears are really three times longer than you thought!

The images from the ultraviolet space telescope are ideal for hunting new phenomena.  The telescope's small, 20-inch primary mirror (not much bigger than a typical backyard telescope) offers a wide field of view. Each image covers 1.2 degrees of sky-lots of territory for the unexpected.

If someone combing the archives does find something of interest, Seibert advises that she or he should first search astronomy journals to see whether the phenomenon has been observed before. If it hasn't, email a member of the Galaxy Evolution Explorer science team and let them know, Seibert says.

So what are you waiting for?  Fire up your web browser and let the discoveries begin!

This article was provided by the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration.

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CONTACTS

Chairman   John Vale-Taylor 

Phil Berry  01892 783544

Treasurer  Mike Wyles  01892 542863

Publicity & Website  Michael Harte  01892 783292

Any material for inclusion in the February 2008 Newsletter should be with the Editor by January 28th  2008

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