JULY NEWSLETTER 2006
INDEX: MEETINGS, OTHER NEWS, CONTACTS
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
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".
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 (75°W) or the western one (135°W),
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.
Chairman
Tim Bance
01732 832745
Secretary
Secretary Phil Berry 01892 783544 phil.berry@tiscali.co.uk
Treasurer
Mike Wyles
01892 542863
Publicity &
Web site
Michael Harte
01892 783292
Any material for inclusion in the August Newsletter should be with the Editor by July 28th 2006