WADHURST ASTRONOMICAL SOCIETY

JULY NEWSLETTER 2006

INDEX: MEETINGS, OTHER NEWS, CONTACTS

MEETINGS

JULY COMMITTEE MEETING

Members of the Society's Committee are respectfully reminded that there will be a meeting of the Committee on Monday July 10th 2006 at the Abergaveny Arms, Frant, beginning at 1930.

As always, any members of the Society are very welcome to come along.

THE JUNE MEETING

Because the June Society meeting fell on the day of the Summer Solstice this year, it was felt that it might be an appropriate time to hold a member's evening when we bring telescopes, binoculars and other astronomical instruments and observing aids used by amateur observers, giving members the chance to talk about their instruments and discuss methods of use and problems encountered.

The evening was also open to members of the public who might be thinking of buying a telescope and wanted unbiased opinions of advantages and disadvantages of different instruments.

In all, members brought along five telescopes, covering a very wide range of lenses and mirrors and illustrating most kinds of arrangements and mounts.

Michael Harte had a very useful tabletop reflecting telescope, ideal for setting up and observing at a moments notice.  The small size also means that the telescope is perfect for transporting with ease to awkward and otherwise inaccessible sites.  Another, not inconsiderable advantage is that this type of telescope doesn't require much time to stabilise with changes in temperature.  Michael also brought his stabilising binoculars.  I have looked through them before and they take out all the strain of trying to hold the image steady whilst giving a useful magnification and without having to resort to a tripod mount.  These binoculars are particularly useful when star hopping, using fainter guide stars.

Gavin Mills brought a tripod mounted 3-inch Newtonian telescope.  It is a sturdy small reflecting telescope and ideal for the amateur astronomer who is looking for an introduction into observing the planets and some of the brighter deep sky objects.  It is capable of producing stunning images of the moon.

Richard Rathbone provided a computer driven 4-inch Celestron Maksutov.  This is a completely self-contained battery operated telescope with its own computer driven software.  This is one of the smallest telescopes capable of making long exposure images.  He uses a Meade Deep Sky CCD Imager to obtain quite acceptable results.  To set the telescope up, it needs to be directed to at least two bright "guide" stars which the computer suggests once the site location has been entered and then it tracks very well.  The computer has 10,000 objects in its memory, which makes it ideal for quick observing from anywhere. 

A very well made 3-inch Newtonian telescope was present.  This was a telescope made by John Vale-Taylor, using recycled parts in a very ingenious way.  For the tube, he had used a waste pipe, with large shaped holes along its side to allow the telescope to quickly reach and maintain the outside temperature.  The mirror cell was cleverly mounted so that the telescope could easily be collimated, and the flat was creatively mounted using more recycled bits and pieces.

The tripod was very solid and again made from converting recycling an old mount.

There was also an 11-inch Celestron Schmidt-Cassegrain telescope incorporating a correcting lens at the front to correct for the spherical mirror.  The light from the main mirror is then reflected from a smaller convex mirror supported in the centre of the correcting lens; the light finally exiting through a hole in the centre of the main mirror to the eyepiece or to a camera or CCD mounted on the back.

This telescope is only just portable and because of the German Losmandy equatorial mount, requires a substantial counterbalance weight.

Unlike the Maksutov, it is driven through a small-computerised drive unit, which can track celestial objects, the Moon or the Sun, and cannot slew to find objects quickly, but has to be manually moved.  Amongst the telescope's additional items was a star vector, which contains 10,000 objects, but to use this, the telescope has to use sensors.  Having entered a required object on the vector, the telescope is then manually slewed to find a minimum sensor reading of Right Ascension and Declination.

A digital projector was used to project images from a laptop using Software Bisque's Sky 6 for members to use and try out.  John Vale-Taylor also used the laptop to display a programme that gave a clever table that showed telescope and lens comparable data where certain specifications could be entered in and then the programme would show the resultant details.

One of our former member's, Murray Barber, sent a number of photographs showing the progressive construction of a ten-foot diameter wooden observatory he is building at his new home in Devon.  He also sent some images he had made using equipment similar to Richard's Maksutov and Deep Sky Imager.  Murray had taken about 50 x 20 second exposures of M101 and using the Meade software had produced a stunning picture with a lot of detail.  He said he had also used PhotoShop to set the blacks.  He also showed other successes he had had with a number of other deep sky objects.

JULY MEETING

Wednesday 19th July 2006 Gilbert Satterthwaite FRAS will be talking to us about "Sir George Airy's Contribution to Positional Astronomy".

The meeting will be held in the Upper Room of the Methodist Church, Wadhurst High Street and will commence at 1930.

FUTURE MEETINGS

Wednesday 20th September 2006.  We welcome back Konrad Malin-Smith FRAS.  This time he will be giving a talk about White Dwarfs.

Wednesday 18th October 2006.  Jerry Workman will be paying us another visit and this time he talks about the latest news from Mars.

Wednesday 15th November 2006.  David Rooney, who is the Deputy Horologist at Greenwich Museum, is to give us a talk called "A Brief History of GMT".

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OTHER NEWS

ASTRO-BARBECUE

As mentioned in previous Newsletters, there will be no meeting in August BUT Michael Harte and his wife are again kindly holding an astro-barbecue evening on Saturday 26th August 2006.  Last year it was a very pleasant evening with members bringing telescopes and binoculars or just coming to join in.

The barbecue evening will be held at Greenman Farm, Wadhurst - on the south side of the B2099 immediately to the west on the railway bridge.  All Society members are invited and Michael suggests that members aim to arrive at 7.00 pm.

You will only need to bring your own food and drink, as everything else will be provided.

Although it is still late August, it can be quite cold later in the evening and it might be a good idea to bring some warm clothing.

JULY NIGHT SKY

Despite the short nights, the Summer Triangle is an interesting area of the sky to consider at this time of year.  It is overhead at present and is bounded at the corners by Deneb, in the tail of Cygnus the Swan; Altair, in the constellation of Aquila the Eagle and Vega, in Lyra the Harp.

Deneb is a bluish-white super giant and is one of the most luminous stars in the sky. It is only the 20th brightest star but is well over 3,200 light years away.  If it were as near to us as Sirius, which we see as the brightest star, it would shine as brightly as the Moon. If Deneb were as close to us as Alpha Centauri, our nearest star at 4 light years away, we could easily read by its light.

Altair means "the flying one," and flies around its axis once every 6 and a half hours. Astronomers calculate that because of this rapid rotation, it must be twice as wide at its equator as at its poles.

Bluish Vega is the fifth brightest star at 25 light years distance and, because of the Earth's precession, will take the place of "The North Star" in about 14,000 years time.

About 3 degrees below Deneb is NGC 7000, the North American Nebula, so called because the shape of the red dust cloud it is composed of, resembles the continent of North America.  The nebula is visible through binoculars under dark sky conditions.

A good object to observe with binoculars is the Veil nebula, NGC 6960, and is about mid way between Deneb and Altair.  This is the remnant of a supernova that exploded about 15,000 years ago and lies about 1,000 light years away.  The nebula covers several degrees and so is well worth looking for with a pair of ordinary binoculars.

Towards the end of July, we begin to get into the meteor shower season with the Capricornids, peaking on the 25th, and the Aquarids peaking about the 30th.  Both are fairly slow meteor showers.

Meteors can be spotted at any time of the years and when chatting after a barbecue on the 24th of June, I saw a very bright slow moving meteor moving from east to west which was breaking up as it passed over head, leaving a trail that appeared to last for a good second.  Not observed, I hasten to add, after drinking quantities of alcohol!

A good example of fast moving fragmenting bright event occur during the Perseid meteor shower and is well worth waiting until they peak on and around the 12th of August.

NASA SPACE PLACE

From Thunderstorms to Solar Storms...

by Patrick L. Barry

When severe weather occurs, there's a world of difference for people on the ground between a storm that's overhead and one that's several kilometres away. Yet current geostationary weather satellites can be as much as 3 km off in pinpointing the true locations of storms.

A new generation of weather satellites will boost this accuracy by 2 to 4 times. The first in this new installment of NOAA's Geostationary Operational Environmental Satellites series, called GOES-N, was launched May 24 by NASA and Boeing for NOAA (National Oceanic and Atmospheric Administration). (A new polar-orbiting weather satellite, NOAA-18, was launched May 2005.)

Along with better accuracy at pinpointing storms, GOES-N sports a raft of improvements that will enhance our ability to monitor the weather-both normal, atmospheric weather and "space weather."

"Satellites eventually wear out or get low on fuel, so we've got to launch new weather satellites every few years if we want to keep up the continuous eye on weather that NOAA has maintained for more than 30 years now," says Thomas Wrublewski, liaison officer for NOAA at NASA's Goddard Space Flight Centre.

Currently, GOES-N is in a "parking" orbit at 90 west longitude over the equator. For the next 6 months it will remain there while NASA thoroughly tests all its systems. If all goes well, it will someday replace one of the two active GOES satellites-either the eastern satellite (75W) or the western one (135W), depending on the condition of those satellites at the time.

Unlike all previous GOES satellites, GOES-N carries star trackers aboard to precisely determine its orientation in space. Also for the first time, the storm-tracking instruments have been mounted to an "optical bench," which is a very stable platform that resists thermal warping. These two improvements will let scientists say with 2 to 4 times greater accuracy exactly where storms are located.

Also, X-ray images of the Sun taken by GOES-N will be about twice as sharp as before. The new Solar X-ray Imager (SXI) will also automatically identify solar flares as they happen, instead of waiting for a scientist on the ground to analyse the images. Flares affect space weather, triggering geomagnetic storms that can damage communications satellites and even knock out city power grids. The improved imaging and detection of solar flares by GOES-N will allow for earlier warnings.

So for thunderstorms and solar storms alike, GOES-N will be an even sharper eye in the sky.

Find out more about GOES-N at goespoes.gsfc.nasa.gov/goes.

Also, for young people, the SciJinks Weather Laboratory at scijinks.nasa.gov now includes a printable booklet titled "How Do You Make a Weather Satellite?"  Just click on Technology.

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          Tim Bance                   01732 832745     timbance@hotmail.com

Secretary        

Secretary        Phil Berry                        01892 783544     phil.berry@tiscali.co.uk

Treasurer         Mike Wyles                   01892 542863     mikewyles@globalnet.co.uk

Publicity  & Web site        Michael Harte               01892 783292        michael@greenman.demon.co.uk

  Editor            Geoff Rathbone               01959 524727   Geoff@rathbone007.fsnet.co.uk

Any material for inclusion in the August Newsletter should be with the Editor by July 28th  2006

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