WADHURST ASTRONOMICAL SOCIETY
OCTOBER NEWSLETTER 2007
INDEX: MEETINGS, OTHER NEWS, CONTACTS
of the Society's Committee are respectfully reminded that there is meeting of
the Committee on Monday the 8th of October at the Abergaveny Arm, Frant starting
As always any full member of the Society is encouraged to come along and join in, make suggestions, give opinions or just have a drink. The Committee do appreciate members' interest and you will not be "press-ganged" into joining the Committee.
to Control a Telescope Remotely
given to the September meeting by Dr Lilian Hobbs
Hobbs is a Project Manager with the Oracle Corporation and is also President
of the Southampton Astronomical Society from where she had travelled to give
this evening's talk. During his
introduction Phil Berry explained that Lilian had agreed to talk to us at the
last minute owing to an unexpected business commitment by our original speaker.
began by suggesting that astronomy in the warm on a cold winter's evening
offered a number of advantages but that this presented a number of challenges in
achieving a working system that didn't cost too much.
of the methods would be to use cables to control a telescope but these would be
vulnerable and the distance could be too far for satisfactory use.
A suitable solution might be to use a computer to control the telescope
and this could also be used to make images using a CCD camera. But in the case of Lilian's garden the distance was 150 feet
and this was still a long way.
story of Lilian's project began back in 2000, when, by following her shares on
the financial markets, the time seemed right to cash them in and with the added
help of "Hector" of Inland Revenue fame the money became available to
finance a small observatory. She
considered various structures. The
most practical would be a BCF dome but later decided on a 7-foot diameter Pulsar
dome which duly arrived on the back of a lorry, already assembled and only had
to be lifted into its final position.
telescope was a 12-inch LX200. A
tripod took up too much floor space so a pillar was erected in the centre.
Later Lilian replaced the telescope with a 14-inch AP1200 but later still
sold it and bought a TMB 7-inch telescope and Astro-physics 4.74-inch telescope
on a Paramount ME mount that she considers to be accurate to less than a pixel
with the result that a finder was not necessary on the telescopes.
control of the telescopes needed consideration.
solution was to use two computers and link them together by means of network
working. As she suggested, many of us have an old computer tucked away
somewhere after they have been replaced with something more up-to-date.
This is usually and old one but is quite suitable to use at the telescope
end. Another consideration was
whether to use cable or wireless. It
was felt that wireless was too vulnerable and slow and the distance was too far,
so industrial standard cable was the answer.
The right length arrived on her desk one day when the remains of a drum
were about to be discarded after some rewiring had been done.
power and the network cable are fed from the warmth of the house through
separate hosepipes to the cold of the dome.
Using the networked computers, Lilian is able to focus and move her
telescope and use a CCD still or video camera.
Two things that have to be done by visiting the dome in person are to
align the telescope when necessary and to turn the roof of the dome, although
the latter might be possible but a lot more expensive.
problem was dampness in the dome and it was found necessary to use a
dehumidifier -remembering to empty out the water before it got too full!
came the control system. Lilian
uses Maxim software but prefers PC-Anywhere, which she says, makes any remote
computer look local even if it is on the other side of the world.
Also mentioned was VNC software, which is free.
VNC is popular but is not as fast as PC-Anywhere.
these remote controlled systems it is even possible to use a small telescope
just outside and then a wireless connection could be used.
word of warning. The telescope can
be left to do its stuff but needs an eye kept on it to prevent accidents such as
attachments falling off or being driven into something and catching cables.
Lilian uses a small infrared security camera that can be monitored on the
network and has the advantage that it doesn't need a light that could affect
viewing contrast. Even so, it can
start raining whilst the telescope is still looking at a clear part of the sky.
systems of remote focussing were tried such as the JMI NGF-S motor focus and
Robofocus. We were told that it was
best to begin trying out the focussing method during the day on such things as
pigeons on TV aerials and then slowly to extend the distance to eventually reach
time is also required and a radio clock was found to be ideal, although those
with GPS systems have one of the most precise sources of time.
process images, Registax, which is free, can be used.
Processing can be done on cloudy nights, during the day or even when
travelling with a laptop on a plane, which Lilian has done on occasion whilst
flying to the USA (and unexpectedly found herself sitting next to a professional
astronomer from Lowell observatory!).
recently Lilian has been using a TV85 and LX200 for wide field observing.
exciting thought was suggested that uses the internet to operate telescopes
belonging to willing amateurs thousands of miles away such as the west coast of
the United States where observers would be going to bed during our daylight
ended her talk by showing a number of images she had made such as M31, the
Dumbbell nebula and a superb image of the Horse Head nebula.
After a large number of questions Lilian headed off back to Southampton having given an excellent talk.
MEETINGS & EVENTS
17th October 2007 Keith
Brackenborough will be giving a talk with the intriguing title "The
Calendar - A 5,000 year struggle to
Align the Clock to the Heavens".
21st November 2007 Details to be
Wednesday 12th December 2007 NOTE: THIS IS THE SECOND WEDNESDAY OF DECEMBER Society Member, Paul Treadaway is giving a talk he calls "Why are we Still Here?" - Food for thought...
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VISIT TO BELMONT HOUSE
Saturday the 22nd of September the Society visited Belmont House deep in the
Kent countryside to have a guided tour of the finest private collection of
clocks in Britain.
Betts, the Curator of Horology at the National Maritime Museum at Greenwich,
took us on a fascinating journey through the world of clocks.
One German clock dating back to the sixteenth century.
Collection was the lifetime achievement of the fifth Lord Harris and numbered
well over three hundred, although only half of them could be displayed at one
time. Even so, Jonathan brought out
one or two clocks that had particular astronomical relevance such as an orrery
clock. Another was a beautiful
pendulum clock displaying the Equation of Time.
were fine examples of Tompion and also Knibb longcase clocks and Jonathan Betts
let us into some of the secrets of terminology in the clock world.
Knibb introduced clocks that had the "IV" instead of the usual "IIII"
on the dial (not "face") denoting that the clock had Roman striking
(not "chiming"). A
"ding" from a high bell indicates each "I" and a
"dong" from a low bell denotes the roman "V".
Two blows from the low bell indicate "X" - ten!
This system was introduced to reduce the drive force required.
also opened a number of clocks to show the incredibly fine work used in the
movement (not "mechanism"), also revealing how even the innermost
parts were covered in beautiful designs.
"novelty room" had a French made clock although retailed in
Birmingham, with a singing bird automaton dating from around 1880.
The birds appeared to hop from branch to branch whilst singing.
The tour lasted well over two hours and was extremely impressive.
NOTES FOR OCTOBER
will not be observable as it passes through inferior conjunction on the 23rd.
is a brilliant morning object at magnitude -4.5 in the constellation of Leo (the
lion). On the 9th of October it passes 3° south of Regulus, and on the 14th it
passes 3° south of Saturn.
in the constellation of Gemini (the twins) continues to brighten to magnitude
-0.6. By the middle of the month it rises before 22.00 BST.
is still visible low down in the west after sunset at magnitude -1.9 in the
constellation of Ophiuchus (the serpent bearer).
is a morning object at magnitude 0.7 in the constellation of Leo.
Below are the events involving reasonably bright (down to about mag 7.5) stars that occur before midnight. DD = Disappearance on the Dark limb, RD = Reappearance on the Dark limb and DB = Disappearance on the Bright limb. The occultation of Regulus on the 7th could be worth watching, particularly to see it "pop out" from behind the dark limb of the waning crescent moon. Times are all BST with the exception of the last one.
|Date||Time||Star (SAO cat.)||Constellation||Mag||Phase||PA degrees|
the 16th and 21st of this month one of the less active meteor showers ( the
Orionids) occurs with it's maximum on the 20th. Unfortunately the radiant which
lies close to the star Betelgeuse doesn't rise until 22.30 BST. However, on the
plus side the meteors tend to be fast and bright and often leave ionised trails
which can persist for a few seconds.
is a comet that was found in the early part of the year and has since been
imaged at magnitude 11 which is brighter than expected. It is thought that it
will become an easy binocular object at magnitude 5 to 6 towards the end of
October. On the nights of the 20th and 21st it will lie just south of the bright
star Arcturus in Bootes (the herdsman).
There are plenty of opportunities to see the ISS this month. Below are listed just the most favourable with respect to elevation and magnitude. Times are BST. For more details log on to the web-site: - www.heavens-above.com
|October Date||Mag||Time||Max Alt||Az|
Summer Time ends on Sunday 28th October at 02.00 hrs.
Leonids maximum occurs on November 18th in the early hours of the morning.
know it's a long way off but did you know that the International Astronomical
Union (IAU) has designated 2009 as the International Year of Astronomy. It marks
the 400th anniversary of Galileo first turning a telescope towards the sky.
Missile in Your Eye
Patrick L. Barry
technology designed to catch ballistic missile launches may soon help doctors
monitor the health of people's eyes.
the last 15 years, Greg Bearman and his colleagues at JPL have been working on a
novel design for a spectrometer, a special kind of camera often used on
satellites and spacecraft. Rather than snapping a simple picture, spectrometers
measure the spectrum of wavelengths in the light coming from a scene. From that
information, scientists can learn things about the physical properties of
objects in the photo, be they stars or distant planets or vegetation on Earth's
this case, however, the challenge was to capture snapshots of short-lived
events-like missile launches! The team of JPL scientists designed the new
spectrometer, called a computed tomographic imaging spectrometer (CTIS), in
collaboration with the Ballistic Missile Defense Organization as a way to detect
missiles by the spectral signatures of their exhaust.
now the scientists are pointing CTIS at another fast-moving scene: the retina of
flowing through the retina has a different spectral signature when it is rich in
oxygen than when it is oxygen deprived. So eye doctors can use a spectrometer to
look for low oxygen in the retina-an indicator of disease. However, because the
eye is constantly moving, images produced by conventional spectrometers would
have motion blurring that is difficult to correct.
spectrometer that Bearman helped to develop is different: It can capture the
whole retina and its spectral information in a single snapshot as quick as 3
milliseconds. "We needed something fast," says Bearman, and this
spectrometer is "missile-quick."
is even relatively cheap to build, consisting of standard camera lenses and a
custom, etched, transparent sheet called a grating. "With the exception of
the grating, we bought everything on Amazon," he says.
grating was custom-designed at JPL. It has a pattern of microscopic steps on its
surface that split incoming light into 25 separate images arranged in a 5 by 5
grid. The center image in the grid shows the scene undistorted, but colors in
the surrounding images are slightly "smeared" apart, as if the light
had passed through a prism. This separation of colors reveals the light's
spectrum for each pixel in the image.
conducting clinical trials now," says Bearman.
If all goes well, anti-missile technology may soon be catching eye
problems before they have a chance to get off the ground.
about other NASA-developed technologies with spin-off applications can be found
article was provided by the Jet Propulsion Laboratory, California Institute of
Technology, under a contract with the National Aeronautics and Space
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Chairman John Vale-Taylor firstname.lastname@example.org
Phil Berry 01892 783544 email@example.com
Mike Wyles 01892 542863
Website Michael Harte 01892 783292
Newsletter Editor Geoff Rathbone
Any material for inclusion in the November Newsletter should be with the Editor by October 28th 2007
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