WADHURST ASTRONOMICAL SOCIETY
NOVEMBER NEWSLETTER 2005
INDEX: MEETINGS, OTHER NEWS, CONTACTS
THE OCTOBER MEETING
This meeting took place at our new venue in the Upper Room of the Methodist Church.
Planets with small telescopes
Talk given by Peter Parish at the meeting on Wednesday 19th October 2005
Peter Parish is the Secretary of the Mid Kent Astronomical Society and he began his talk by saying that it is not always necessary to observe the planets through substantial telescopes and he himself does visual work and uses neither film nor CCD cameras.
For many years Peter has drawn the planets on specially designed templates. He pointed out that the atmosphere has considerable effect on the visibility of the planet being observed. There is 5 miles of atmosphere looking vertically into the night sky and 200 hundred miles looking over the horizon. Visual observers use the Antioniadi Scale which provides a 5 scale measure of the visibility of an object. Perfect conditions returns 1 and continuous tremulations, often vigorous returns 5, the lowest quality of viewing.
Peter's templates are in the form of a card about the size of a post card with an area representing the planet being observed, surrounded by a black area. Depending on the phase of the planet the area can be reduced with black felt-tip pen to fit the visible part of the planet. He then uses a 2B pencil to sketch the surface features and by using his finger or an eraser, blends the graphite to match what is being observed.
In this way and using careful shading Peter considers that he becomes more familiar and "sees" more that he does when photographing the planets.
Although the drawings are in black and white he makes notes on the template of any colour he sees. He can also make notes of the Antioniadi scale, phase and any other relevant data.
He feels better results are obtained using refractors and, to increase the contrast, uses an Orion 21 orange filter.
Peter's cards record many changes over the years from storms on Mars and of changes in the weather patterns in the equatorial regions ofJupiter and Saturn, showing that in 10 minutes there can be quite a change.
Finally we were shown photographs Peter had taken during the transits of Mercury and Venus but most striking of all were his many superb drawings recorded over many years and revealing that by drawing the planetary features one can sometimes see details missed in photographs.
The November meeting will take place on Wednesday 16th November 2005 at our new venue in the Upper Room of the Methodist Church, opposite the gates to Uplands College where we used to hold the meetings.
The meeting, which begins at 7.30 pm., will include a talk by Bob Turner FRAS. The talk this month is "All the Things that could Kill me" and Bob invites members to bring along pen and paper. So it could prove to be an entertaining and instructive evening; or perhaps a warning! This is a change from the original programme.
Wednesday 14th December 2005 NOTE: this is the second Wednesday of the month This is the Annual General Meeting of the Society.
There will also be a talk by Bob Seaney, a Society member, talking about "Shedding Light on Light". All followed by hot mince pies!
Wednesday 18th January 2006 Dr John Lawrence gives an illustrated talk on "The History of the Telescope"
Wednesday 15th February 2006 Dr Martin Heath presents a talk with the intriguing title of "The Habitability of the Red Planets".
GO TO INDEX
SOCIETY TRIP TO BAYFORDBURY OBSERVATORY
The Society trip arranged by Ian King to Hertford University's astronomical facility at Bayfordbury Observatory proved a well worth visit. Nik Symanek showed us round most of the eight domes. Sadly the clear sky lasted for just the first half hour and didn't really give us the opportunity of observing.
At the middle of each dome was a solid concrete plinth to mount the telescopes.
The facility housed the large Marsh 20-inch cassegrain telescope named after the first director of the observatory. The three main telescopes were 16-inch Meade LX200EMCs, and each was being used for different observing purposes such as CCD imaging and spectroscopy. In another dome was an older Celestron 14 inch catadioptic telescope with a C9 saddled on it.
We were also shown the Henry Brenton 10-inch Newtonian telescope, although it looked as though it was rarely used now.
Finally we were invited into the main observatory building for coffee and what developed into an interesting discussion on observing techniques and how the astrophysics courses were run.
SUBSCRIPTIONS ARE NOW DUE
Members are reminded that subscriptions for the next session of the Society become due on the first of November 2005. The subscription remains at £15 per member and £20 joint membership.
NASA SPACE PLACE
A Wrinkle in Space-Time
By Trudy E. Bell
When a massive star reaches the end of its life, it can explode into a supernova rivalling the brilliance of an entire galaxy. What's left of the star fades in weeks, but its outer layers expand through space as a turbulent cloud of gases. Astronomers see beautiful remnants from past supernovas all around the sky, one of the most famous being the Crab Nebula in Taurus.
When a star throws off nine-tenths of its mass in a supernova, however, it also throws off nine-tenths of its gravitational field.
Astronomers see the light from supernovas. Can they also somehow sense the sudden and dramatic change in the exploding star's gravitational field?
Yes, they believe they can. According to Einstein's general theory of relativity, changes in the star's gravitational field should propagate outward, just like light-indeed, at the speed of light.
Those propagating changes would be a gravitational wave.
Einstein said what we feel as a gravitational field arises from the fact that huge masses curve space and time. The more massive an object, the more it bends the three dimensions of space and the fourth dimension of time. And if a massive object's gravitational field changes suddenly-say, when a star explodes - it should kink or wrinkle the very geometry of space-time. Moreover, that wrinkle should propagate outward like ripples radiating outward in a pond from a thrown stone.
The frequency and timing of gravitational waves should reveal what's happening deep inside a supernova, in contrast to light, which is radiated from the surface. Thus, gravitational waves allow astronomers to peer inside the universe's most violent events - like doctors peer at patients' internal organs using CAT scans. The technique is not limited to supernovas: colliding neutron stars, black holes and other exotic objects may be revealed, too.
NASA and the European Space Agency are now building prototype equipment for the first space experiment to measure gravitational waves: the Laser Interferometer Space Antenna, or LISA.
LISA will look for patterns of compression and stretching in space-time that signal the passage of a gravitational wave. Three small spacecraft will fly in a triangular formation behind the Earth, each beaming a laser at the other two, continuously measuring their mutual separation. Although the three 'craft will be 5 million kilometres apart, they will monitor their separation to one billionth of a centimetre, smaller than an atom's diameter, which is the kind of precision needed to sense these elusive waves.
LISA is slated for launch around 2015.
To learn more about LISA, go to http://lisa.nasa.gov. Kids can learn about LISA and do a gravitational wave interactive crossword at:
This article was provided by the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration.
ASTROADVENTURES, THE FIRST 9 MONTHS!
News from Murray and Valerie Barber in deepest Devon
We moved to Bradworthy just before Christmas 2004 and were joined by our friend and business partner Tony Gibbons in mid-January. One of the very first things we did was to plan out the position of the observatories, in particular the first of three. They are referred to as OB1, OB2 and OB3 with last one to be a dedicated imaging facility in a dome. OB1 and 2 are to be run-off shed-type structures containing the large Dobsonians we have. We positioned OB1 taking account of mature conifer bushes set as intersecting lines meeting at right-angles. This is a perfect position because we have excellent coverage of the sky with a degree of shelter and natural masking caused by the greenery. We started work on OB1 in the last week of January and it was completed in early March. The floor of OB1 is raised to avoid the damp and the half metre telescope sits on a separate base to isolate it from floor vibrations. OB1 is powered by car batteries for safety and has proved to be very popular with guests because at very short notice we can dismount the half metre and quickly set up an equatorial telescope. At a moment's notice the roof can be rolled back and the telescope can be in action !
In April we laid an area of 'hard standing' so guests can set up scopes independent of OB1 and this proved very useful especially when both of our lets were occupied by astronomical guests.
The skies here in north Devon are very dark with the only noticeable light pollution emanating from Bradworthy which is about 2 miles to the north of us. If you have to have light pollution it's always a good idea if it's to the north and not to the south! During March and April, the Zodiacal light was plainly seen as a faint cone of light to the west and we have been amazed how bright the Milky Way has been even in late September. Recently we have enjoyed wonderful views of Mars even with the big Dobsonian which now sports new side bearings and critically adjusted optics thanks to our new Howie Glatter holographic laser collimator.
With the opposition of Mars coming up this autumn, we decided to concentrate on the imaging observatory, OB3. We have now installed a permanent pier to support our new EQ6 Sky Scan mount and around this we will build a semi-spherical dome that can easily accommodate our image scope, a 10" F.5 Newtonian. The roof will be a fibreglass structure and the wooden buck has already been constructed. Although the construction for OB3 will miss Mars this opposition, it should be complete by the year's end. As a temporary measure, we have constructed a moveable windbreak so that even from the middle of the field we can easily webcam Mars without being unduly troubled by the wind. We have posted our Mars images on our web site and hope to expand this with Saturn and Jupiter as the season progresses.
We have already had return visits from astronomers who enjoy our faculties and this autumn we will be entertaining our first astronomy society groups. We also have guests that have booked simply to enjoy an ordinary holiday but have then been 'hooked' by our interests. So although we have had 'ups and downs' with such an enormous life and business change, we have survived the first nine months and are very hopeful that we will be able to build on our success to date. We send greetings and best wishes to our friends at the WAS and perhaps it might not be too long before we see you here in north Devon!
Chairman Tim Bance 01732 832745
Secretary Ian Reeves 01892 784255
Treasurer Mike Wyles 01892 542863
Publicity Michael Harte 01892 783292
& Web site firstname.lastname@example.org
Editor Geoff Rathbone 01959 524727
Any material for inclusion in the December Newsletter should be with the Editor by November 27th 2005