WADHURST ASTRONOMICAL SOCIETY
SEPTEMBER NEWSLETTER 2005
INDEX: MEETINGS, OTHER NEWS, CONTACTS
PLEASE READ THE SECRETARY'S IMPORTANT NOTICE AT THE END OF THE NEWSLETTER
Konrad Malin-Smith arrived with a suitcase full of aids for his
demonstrations. He began his talk
by showing an analogy of the twinkle of a star by passing a large torch through
rippled glass, the effect being slight undulations in brightness.
Using a point source through the same piece of glass we could see a very
obvious twinkle, demonstrating the relative effect of source size.
Jocelyn Bell, a graduate student at Cambridge University was working
towards her Ph D under Anthony Hewish when in 1967 she was operating the huge
81.5 MHz radio aerial she had helped construct using 9,000 wooden poles which
supported the receiving wire used to observe radio signals from distant Quasars.
Her job was to analyse the radio signals received as the earth rotated
since the array itself was fixed. As
the array scanned the sky she noticed a period of very rapid pulses amongst the
data. Jocelyn Bell had detected the
first pulsar although at the time it was christened LGM - "Little Green
The rapid pulses suggested that the source must be a rapidly rotating
neutron star that had collapsed under enormous gravitational pressure.
The resulting fast spin being similar to that of a spinning skater
drawing her arms in to her sides.
The giant Aricibo telescope in Porto Rico was used to observe the pulsar
since this aerial could be steered up to a point and then subsequently the fully
steerable Jodrell Bank radio telescope in Cheshire was used.
In 1968, Jocelyn Bell looked in the general direction of Perseus using
21.5 MHz, the absorption radio frequency of hydrogen and observed CP3028, a
pulsar calculated to be 6,000 light years away with a diameter of 6 miles.
The pulsar had to be a neutron star to withstand so many rotations per
second without flying apart.
Molonglo radio observatory near Sydney used a Mills Cross array to
observe an object in the southern end of the Veil Nebula.
A pulsar was discovered at its core, rotating at 11 times a second.
It was estimated to be a young pulsar resulting from a supernova that had
taken place about 50,000 years ago.
A more recent supernova occurred in 1054 and was recorded by Korean
astronomers. It was so bright that
it was even visible during the day. Modern
astronomers have identified the event as that which created M1, the Crab Nebula
as we see it after nearly a thousand years.
Konrad demonstrated the effect of polarized light using two polarizing
filters and rotating them so that light through both reduced to nearly zero when
at 90 degrees.
It was discovered that the Crab Nebula radiates polarised light and it
was also noted that the light from the Veil Nebula was 90 % polarised.
The pulsar in the centre of M1 rotated at 30 times a second and Lick
Observatory made a light-intensity-graph through a rotating shutter that
revealed the regular pulse.
To demonstrate the way in which we "see" a pulsar Konrad
returned from his suitcase with a model built by one of his students.
The pulsar was represented by a sphere about the size of a tennis ball
with projecting pipe cleaners on opposite sides to represent the narrow beams.
A light inside shone out in line with the two sets of cleaners.
The whole fitted on to the end of a battery screwdriver that slowly
rotated the model so that we could see how we would only "see" the
pulsar when we were in line with the beams.
The outer crust of a neutron star would have to be very strong to prevent
it flying apart, and it has been calculated that this would be in the region of
ten-to-the-eighteenth times the strength of steel.
An over exposed photograph of the Crab revealed the wispy structure as a
cylinder of hydrogen with the pulsar at its centre.
The Crab was the result of a Type 2 supernova.
A Type 1 supernova has no hydrogen.
A slide of The Crab Nebula taken in X-ray radiation revealed further
structural details and further research is still uncovering yet more
After the talk was over, a question of the rotation of a neutron star was
put by one of our members, and amazingly Konrad went to his suitcase and
produced a box of 6 eggs! He explained that one of the eggs was hard boiled and the
others were fresh and proceeded to demonstrate a way in which the odd egg could
be determined by spinning each egg on its longest axis in turn.
The hard-boiled egg spun for some time but the raw eggs wouldn't spin.
He explained that the glutinous contents dispersed the energy inside the
egg leaving little or none left in a coherent direction to spin it.
The question of why he had eggs in his case that he hadn't intend to use
in our talk never got asked...
It was an excellent talk presented in a way that only Konrad Malin-Smith
could have done.
The next meeting of the Society is on Wednesday 21st of September 2005
when the speaker will be Alan Drummond talking about "Perception in
The meeting takes place in the Drama Studio at Uplands College starting
at 7.30 pm. The entrance to the
studio is the first door on the left through the College gates.
This will be the last time we meet at this venue!
(See the Secretary's notice later in the Newsletter)
Future meetings will be held at the Upper Room at Wadhurst Methodist
Church opposite Uplands College.
19th October 2005. Peter Parish
introduces us to "Planets and Small Telescopes"
16th of November. The speaker
will be Gilbert Satterthwaite talking about nineteenth century instruments with
a particular interest in Sir George Airy. The
talk is called "Positional Astronomy".
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The Astro Barbecue on Saturday 27th August and hosted very kindly by
Michael Harte and his wife at Greenman Farm was great fun.
Several members brought telescopes and the sky was exceptionally clear
with virtually no light pollution. The
Milky Way was very clear with the dark lanes being prominent.
Two very bright meteors occurred and judging by their origins looked as though they could have been late runners from the Perseid meteor shower.
VISIT TO HERTFORD UNIVERSITY
As mentioned in the Summer Notices sent to members on the 10th of August,
Ian King has very kindly offered to arrange a guided tour of Hertford
University's astronomical facilities at the Bayfordbury complex, just over a
mile outside Hertford town, provided enough members are interested in going.
The visit would take place on Friday 21st October 2005, meeting at the
site at around 7.30 pm. Members
would need to make their own travel arrangements or share cars to the centre.
We can discuss this at the September meeting.
Our guide would be Nik Szymanek who has talked to the Society before and
is also featured in the August edition of Astronomy Now, so it can't help but be
a very interesting and informative evening.
Ian would like to know the names of interested members by, or at the September meeting of the Society on Wednesday 21st September 2005. If you need to contact Ian, his telephone number is 01892 836288 and his email address is email@example.com
NIGHT SKY IN SEPTEMBER
The nights are lengthening and the sight of the Pleiades means that the
winter constellations are not too far away.
But there is still a chance to try and find M57, the Ring Nebula in Lyra
to be found just 6 degrees south of Vega midway between the two magnitude 3
stars, Sulafat and Sheliak. Worth
Mars is not far from the Pleiades rising soon after nine, although until
the beginning of October its orbit appears to be retrograde.
POLLUTION AROUND WADHURST
Phil Berry, one of our members, alerted other members in the Wadhurst area about proposed lighting over a private tennis court that would have been quite intrusive during the evenings. As a result many local members wrote to the local council and I am delighted to say that the protest was successful and it has just been announced that the proposal was rejected.
IMPORTANT NOTICE FROM THE SECRETARY
The Society meetings have been held in the Drama Studio at Uplands
Community Centre (UCTC) since 1997 at no cost until 2000 when cost of hire was
set at £137.50. Since then it has
risen to £316!
We have also been very fortunate indeed to have enjoyed, through Chairman
Tim's generosity, 5 years of refreshments and during the past 2 years Amina
and Chris Green have made all the arrangements to ensure that we were refreshed
at each meeting.
The time arrived to seriously review the high cost of the meeting room
and to take the pressure off Amina and Chris.
Following the Committee meeting on 11th July enquiries were made to try
and lower hiring costs in accommodation where there were existing catering
The Committee has arranged to move our meetings to the Upper Room at
Wadhurst Methodist Church COMMENCING 19TH OCTOBER 2005.
Entrance to The Room is situated on the OPPOSITE SIDE OF THE ROAD about
half way between UCTC and the Greyhound pub.
The Secretary will endeavour to have the Society Banner on display
outside the premises. Parking is
available behind the Greyhound if St. James Square is full.
The room is centrally heated and there is wall-to-wall carpeting.
It is clean, tidy and devoid of extraneous theatre props and clothing.
Catering equipment is installed including a warming oven (for AGM mince
pies). What is more the cost is 53%
less that UCTC.
DO REMEMBER that our meeting will be held at UCTC as usual, yes Uplands,
on 21st September so that any members who are on holiday or miss this first
advice of a change of venue do not get hopelessly lost.
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