BBC Sky at Night;-
May's programme focuses on Mars and the 10 years of Mars
Rovers. It is now available on iplayer, don't miss it.
The velocity of
Light - National Astronomy Week 2014.
It was Ole Romer, the Danish
astronomer, who made a set of observations between 1671 & 1677 and
based on best estimates of distance at the time to calculate a
reasonable figure for the speed of light. The technique he used was
based on eclipses of the satellites of Jupiter. Romer like
scientists before and after him “stood on the shoulders of giants”
to advance his work.
It was Copernicus in 1543 who
suggested that the Earth and all the planets orbited the Sun.
Kepler in 1609 and 10 wrote his 3
laws the last of which stated that T 2 = R 3 this is easy to
interpret if T is in years and R in astronomical units. This allowed
astronomers to define the distances in terms of the AU for all the
planets of the Solar System. Galileo saw the moons of Jupiter in
In 1678 Newton unravelled gravity G
to give a quantitative interpretation of Kepler’s Laws. GCSE Book
Naturally enough Jupiter was
studied in detail and the time it took Jupiter’s satellites, Io in
particular, to go behind Jupiter in eclipse was measured accurately
The image which follows shows Io transiting the planet and also
includes the Great Red Spot.
Image Credit Paul Clarke
"The satellites move from east to
west across the face of the planet, and from west to east behind it.
After conjunction with the Sun and before opposition, the shadow of
Jupiter falls to the west, eclipse precedes occultation, and
shadow-transit precedes transit. After opposition, the order of the
phenomena is reversed, occultation preceding eclipse and transit
preceding shadow-transit.” BAA Handbook 2014. Due to fact that
Jupiter was past opposition during National Astronomy Week it will
only be possible to use the time of emergence of Io the innermost of
the moons of Jupiter.An analysis of the times that Io remains
eclipsed showed a steady increase from the beginning of January,
when Jupiter was in opposition , until early June when it is in
conjunction with the Sun. National Astronomy Week website.
the actual Society running
this event for NAW is Orwell AS
To keep an eye on Jupiter the
planetarium programme “Stellarium” not only tells the observer
which moon is Io but also the distance of Jupiter from Earth. Over a
period of time as the distance increases so does the length of time
in eclipse, when two or more results have been obtained the speed of
light can be calculated. Clearly the more results obtained the
closer we get to a true figure of the speed of light. The plan is to
submit timings to Orwell and they will do the calculation! NB
Stellarium can be downloaded from
it is free and works on most Computer Platforms.
There was one problem faced by the
early astronomers – they were able to obtain comparative figures of
distance from the Sun but an absolute distance eluded them. However
the transits of Venus 1761 and 1769 allowed rough figures to be
obtained. Better figures were obtained in 1874 and 1882 and they
were analysed afterwards by Encke. See The Midnight Sky p191
see also Jeremiah Horrocks by Paul Marston. Clearly these
events had not yet taken place in the 17th cent so an alternative
must have been used.
It is well known that Gill in 1877 measured the parallax of Mars on
Ascension Island. Dic. Scien Bio.p417. Perhaps this too built
on earlier work?
Jean Cassini, although he rejected
the idea that light had a finite velocity nevertheless was the first
to arrive at a figure for the distance of Mars in 1672. He took
advantage of a good (early September) opposition by sending Jean
Richer to Cayenne, on the north east coast of South America. Cassini
stayed in Paris at the Paris Observatory. This gave a baseline of
nearly 10,000 km for a triangulation of Mars. The results derived
for the AU were 138 million km about 11.6 million km less than the
value accepted today. Dic Scien Bio p221
Romer used Cassini’s results to measure the speed of light. He was
aware that the length of time between eclipses of Io was not
constant. He calculated the time in 1675 (early June) when Jupiter
would be closest to Earth i.e at opposition and observed that at
that time the interval between eclipses was also smallest. He
continued for a number of years taking measurements. In Sept 1679 he
announced that on the 9th November the eclipse would actually take
place some 10 minutes later than other astronomers had predicted. He
was of course correct and stated that the cause was the extra
distance the light had to travel as the distance between the two
planets was now larger than before. He calculated the speed at
225,000 km/sec pretty close to today’s figure of rather less than
reading;- The story of
the heavens by Robert Ball pub1890 on P222
Outlines of astronomy by John
Herschel pub 1869 on P364.
Astronomy by Flammarion published
in French 1880 translated from the French edition 1955-60
translated, revised and updated 1964 P303 et seq.
Tuesdays Life and
death of stars - with Clint.
Tuesdays Astronomy for Interest - with Brian
Wednesdays GCSE Astronomy - with Brian
Astronomy for interest is our basic entry level course for new
comers to the sport. Life
and death of stars is a little lower than A Level
All courses start;-
and finish at 9.00pm and are £5.00 per night. Courses are 10 weeks
long except the GCSE which runs until May. "Astronomy for interest" and
"Life and death of stars" on Tuesday
GCSE Astronomy Wednesday. Contact Brian Sheen
(01726) 813602. email
experience for years 10 & up;-
Interested students should contact their
school coordinator as soon as possible.
See also the News Page. All
letters and correspondence must go to the Par Office,
92 Par Green, PL24 2AG. and
the Observatory site.
We are recruiting for 2014 now!
UK's very own Space
Weather forecast;- From the Met Office Exeter
will come the UK first Spaceweather forecasts,
they will start in May 2014 i.e in a matter of days.
Naturally RAL Space the source of many of the
instruments on the various Solar Observatories is heavily involved.
However we will have to wait before Solar Orbiter launches in
January 2017 to get our closest views of our Star.
Prominences and active areas on the surface of the Sun.
An archive image taken through our H Alpha scope.
Mike in the
my main man up there has got his new website
running well - check it out it even links back to this one! He has
just added Curiosity to his range of card models you can down load
for free. Please note this one is 101 MB - just like the Dalmations.
For the work we
did together at Stargazing LIVE 2013 Mike made a model rover as a
prize that was won by Thomas. Saw the lad again last week and he has
the Rover proudly displayed in his room!
Mike's model of Curiosity -
this one is in Shetland not Mars.
Bodiggy School paid us a visit a few days ago
here is some of the evidence
April Night Sky
Don’t miss it;- Mars is the "star" of the month – the
original "wandering star" no less. It is at its closest to
us for the next two years, given clear skies it will be
possible to see the Polar Caps and some of the dark patches
on its surface. The Observatory will have some of its scopes
focused on the Red Planet most clear nights, just check
before turning up.
Constellations;- This month sees a welcome return
of Deneb and Vega two stars of the "Summer Triangle" a sure
sign that Spring is here. Take the opportunity to look for
M13 in the keystone of Hercules the giant globular cluster
can be seen with a binocular or small telescope. April is
one of the better months for being out of doors. It is not
so cold and yet is gets dark at a reasonable hour.
The Moon;-, New Moon 30th (March) ,
First Quarter 7th, Full Moon 15th.,
Last Quarter 22th, New Moon 29th.
Total eclipse of the Moon on the 15th - visible over most of
the world except the UK.
The Sun;- An Annular eclipse of the Sun on the 29th
- visible as a partial in Australia.
Note the linkage between the Lunar and Solar eclipses it
is not a coincidence!
Mars;- At its best for two years - close to the
bright star Spica in Virgo. Really good for most of the
month, it will be good to catch a glimpse of its distinctive
features in a telescope.
Jupiter;- rises in the East and is up most of the
night– check out its four moons and watch them dance around
the planet night by night. It is now past its best but
always a great object in a telescope.
Saturn;- Is in Libra and therefore close to the
horizon when seen from the UK, never the less its rings are
always good to see.
Meteor Shower;- The first meteor shower for a
while, the Lyrids peak on the 22nd but can be
picked up a few days either side of this date.
International Space Station; As usual check exact times
Astronautics Badge;- The UK Space
Agency have sponsored a new Scout Badge. We are
investigating the best way of delivering this to Cornish
The Hurlers;- A combined project with the county archaeologists culminated
in a nine day "Summer School" on the Hurlers. Called "Mapping the Sun"
Involved survey work and mapping the Sun rise and set
positions. We have created a Bronze Age Landscape map -
working with a range of specialist kit new and old to achieve this.
New Discoveries were made and new Legends were born. The archaeologists
uncovered, examined, photographed and recorded a quartz pavement that last saw the light of day in 1938
and using modern techniques will learn so much more. Some of our research work can be found on this
page see below;-
Orion's Belt on Bodmin Moor.
The image was taken, with great expertise, by Tony
Piper located on Caradon Hill. Single torches were placed in
each of the circles. The result shows how closely the torches
resemble the stars in Orion's Belt.
This lovely sunset picture showing two of the Hurlers
lit torches was taken by
Paul Hughes of the Observatory team
Stop Press - Equinox problem solved. The
Sun did not rise and set as expected this problem has now been
addressed with a little help from my friends.
NB The first rough draft has been prepared, images
have now been inserted and then GPS and other data. It will then be
released on macastro. Watch this space!
Martin, a German visitor to Cornwall filming the
Hurlers from his Quadrocopter.
His You Tube videos can be found on Thesnaptin
Image Credit Robin Paris
On this web
site;- Much further down this page you will find an
account of some the research that has gone before.
Good News;- The Par Community Association has been
supported by a grant of £660.00 towards installing the Sphere.
Cornwall Council is working out the best way to get the Sphere sited
to great advantage. Now getting down to a Business Plan! Now have
quotes in and a number of options so things are on the move.
Part of the
Paralympics is in Cornwall - it is an Armillary Sphere
Image credit Sonia Clyne.
Joe Warrener who
spent a few nights at Court Farm took this excellent view
across the site.
The Pelican Nebula an emission nebula in Cygnus.
Image Credit Paul Hughes
To see all of Paul's
images at full resolution go to www.zenfolio.com/paulh101
a lot of detail has been lost on the web page. His favourites file
can be run as a slide show covering a range of deep sky objects.
If you go down to the woods tonight .....! Image
Shetland Astronomical Society; I was in Shetland in the summer 2011 working with the SAS. Check out
www.shetlandastrosoc.org.uk To see
Mike's - austroastro's video made from Chris Brown's images of the
click on the link. For other U tube videos by austroastro do a Google search.
Science Technology Engineering Maths Ambassador;-
or STEM for short. Mainly for those wishing to get involved teaching
with the Observatory. This is a National approval scheme that allows
us to teach/demonstrate in schools and youth groups. Any one can
apply (including those outside our team) is is good for those asked
to go into schools to represent the companies they work for, Includes
a DBS. To learn more contact us via any of the Observatory
A great link
from an American fan;- Matthew H. found A kids
Space Centre - Fun with Model Rockets - (http://orlandofuntickets.com/a-kids-space-center-fun-with-model-rockets.php)
while working with his local library.
Mike working on the
An image credit Rob Stidston
Have your telescope in two places at
Well with Slooh you can.
A good way
to be able to image almost anywhere any time with your
"own" Robotic Telescope. The Observatory has a
The Space Station is visible in our skies from time to
time. See www.heavens-above.com
for exact times for you. There are chances to see it in the
daytime and towards dusk when it is getting dimsy.
It Is so bright
that it will flare as the Sun strikes one or two of the large solar
H-A are now giving suitable times for daylight passes.
Opportunities for schools
For more information about the courses see the
"NEWS" page and then contact the Observatory.
Work Experience years 10 & 12;-
Our very successful WE programme enables students to take a genuine
part in the work of the observatory as trainee astronomers. Apply
now for 2014 to the Par Green address and not the Observatory site.
Key Stage One, Two and Three Astronomy.
Opportunities throughout the Year just phone and
book, more under News page on this site.
Beyond; Doing Space this term then
school teachers should see our News section.
& Talented sessions for years 10 & 12
at the Observatory.
Astronomy Practical Project work. Having successfully guided many
students through the GCSE Course work we offer opportunities
on a regular basis. Opportunities throughout the
year just phone and book.
£5.00 per session.
each case email email@example.com
or phone (01726) 813602 to learn more.
Extended project A Level
std. Global Dimming. This
experiment was extended this year into the IR as it produced a clearly measurable change
in light levels through the previous Christmas period.
Scouts, Guides and other youth groups see the separate
RESEARCH AND SPECIALS
The Neptune Saga;- Continues with a
new book about Le Verrier which fills a black hole in our knowledge
of 19th cent. French Astronomy. Written a
review for publication in a number of journals. Also the long
awaited paper on the subject has now been published see below in the
main Neptune section. Anyone wishing to read it please request a PDF
Our Neptune research
has reached the august pages of the Antiquarian
Astronomer issue 7 March 2013. it covers some 11 pages and is
described as "incisive".
during the Society for the History of Astronomy autumn conference
year;- The year 2010 opened in January with a
special presentation in Seattle, USA. NB The Blue Planet is close to
opposition at the moment so a good time to observe given clear
Image credit "a friend"
Note the Cornish Flag!
Credit;- Jocelyn Murgatroyd and Cornish Cross Laneast
by John Chiswell from two cameo reliefs. The lady is Eliza
Adams nee Bruce - It is believed to be the only likeness in
existence. The sculpture was by Albert Bruce-Joy a relative and well
This image is of the memorial in
Westminster Abbey and is also by Bruce Joy. Image Credit Westminster
Bill Sheehan's Neptune with 10" RC.
Neptune discovery story.
For a short film of the Neptune story
visit Maarten Roos website. http://www.lightcurvefilms.com
Have continued my researches
by contacting the Chinese University in Hong Kong (been there got
the T.Shirt). Some 10 years ago they did some excellent work on
Neptune's orbit which I now have permission to use in my talks.
For Canoe Africa see below.
Site;- We are currently
working with Caradon Archaeology on The Hurlers.
(Minions is the nearest
work is centred on how to best interpret these ancient sites to an
interested general public. At the moment we
are helping with an APP to interpret the area in a modern way. Thanks to Cornwall Council and Cornwall Heritage Trust for
their support. The App is now on a an APP store but in a Beta Version to be
tested by those involved.
background;- The Hurlers can be
found on Google Earth 500 30' 58.67"N 40 27' 29.69"
W, the aerial view is supplemented by a number of photographs and
some text. Until recently people studying the various monuments around
the country would look closely at one aspect or site and not regard those
near by. The Hurlers are the focus of a much larger complex of ancient
Back to the
Hurlers. Lead by Gary and supported by Amanda we measured
the elevation of Rillaton Barrow above the horizon step by step
using a professional level. We had good results although more
work needs to be done. We have proved which star it
celebrates and when it was built. We seem to have identified the
Processional Way referred to by John Barnatt in "Prehistoric
Calendar Stone is to be found in the Centre Circle and to
the south of centre. For all time people have noted that
shadows cast by trees or stones change their length and direction
during the day and throughout the year. The length marked at midday
once a month requires only 7 marks to define the solar year. A more
complete explanation of this system is available.
Archaeologists are often rightly sceptical of two point
alignments and require either a Back Sight or Fore Sight to support the
evidence. Extend the Hurlers SW - NE line northwards about a kilometre to
arrive at Tumuli. Due north is Stowe Hill due south is Minions Mound with more Tumuli. (Tumuli
are Bronze Age burial sites.) Due East is Kit Hill due west is a large
barrow. If you turn your back on Kit Hill and look towards the Pipers you will
find they lie one behind the other i.e. due west. Stand between the Pipers and
look towards Stowe Hill and you look North. Are the Pipers contemporary with the
Hurlers - the evidence points in a positive direction.
The N - S line can be extended on to Long Tom, Menhirs or
Long Stones predate Stone Circles and this one has had a Cross carved on it at a
later date. Although not exactly due south of the Hurlers it is south of
Stowe Hill which is a long ridge of high ground.
Equinox;- To celebrate this we visited the Hurlers
on the Sunday 25th March 2012 Sunday AM was good in that it
was clear and we saw the Sunrise, close to Kit Hill although Kit Hill itself was not
visible to the naked eye due to general murk. Sunday PM saw the Sun
setting due west close to a couple of burial mounds as predicted.
Summer Solstice;- It so happens that
the midsummer Sun rises above Stowe's Hill and sets over Brown Willy. Summer Solstice
21st June and we were at Craddock Moor Circle for the event. A first for us was an observation of a
special Standing Stone on Stowe Hill It seemed to mark the actual
position of sunrise. (June 2010)
From Craddock Circle the Sun rose behind the Cheesewring on Stowe Hill as predicted, what was new
to me was to see the Sun hitting Tregarrick Tor before it rose for
us, this confirms that Tregarrick marks the winter solstice sun set.
(June 20th 2012)
The Sun rising over Stowe Hill (2012)
Image by Amanda King of the
Summer Solstice 2013;-
The group ambled out Craddock Circle. It is a
circle of fallen stones close to gorse bush atop a featureless
hillock. The Sun had shown signs of remaining visible until sunset
but it was not to be. However it appears to set just west of Brown
Willy. Images had been taken a couple of days before and will be
examined in the Observatory.
Many thanks indeed for the images
from Robin Paris of Darite - excellent and revealing sunsets. A CD
has just arrived with more images all adding to our overall
knowledge of the Bronze Age calendar.
The Sun rose and set as per the Vernal Equinox, although on the date we
were there (21st Sept. 2011) the fog was so thick it was impossible to
see across the Circles!
This time using a solar filter in conjunction with
a small telescope it was possible to determine that the Sun rose
just a bit to the right of Kit Hill stack. The sunset was impossible
due to thick cloud. 22nd Sept 2012. Same situation Sept 2013.
The three stone circles known as the Hurlers near
Minions, Bodmin Moor. Appear to mirror the well known asterism of Orion’s
Belt in the centre of the Orion constellation.
21st Dec Mid
Winter Solstice 2013;- Usual pea souper
of course up on the Hurlers - Bodmin Moor, so we were unable to do much until after breakfast. The
modified compass worked well to gave us a real baseline for the
first time. Checked out Kit Hill again as due East and established
the position of the "4th circle". We were unable to do the Sun rise
from Craddock Circle. Just too foggy at sunrise.
In the 21st cent. this constellation, including
Orion’s Belt, is due south of the Hurlers on the
winter solstice (Dec 21st) at midnight. In the Bronze Age
circa 2000 BC this transit occurred earlier in the evening due to precession.
Remember the actual day of the winter solstice was marked from Craddock
Circle. Due north was marked by Stowe's Pound and the “ever present” pole
star, in those days Thuban in Draco and later Kocab in Ursa Minor. Directly north of the Hurlers is Stowe Hill with its Neolithic
enclosure and Rillaton Barrow, the Bronze Age users of the Hurlers would have
recognized that the stars directly above the Hill did not move and were
therefore special. Today the star that occupies that place is called the Pole Star,
North Star or
There is no doubt
that the view of the Hurlers would have been very special before the Quarry
removed much of the viewing area. However even today the torch lit Circles look
Paul Hughes of the Observatory Imaging Team
The Three Circles lit by torches, giving a very atmospheric
effect. It seems that at this time the
winter solstice was celebrated all over Europe by the lighting of bonfires. It consists of four individual images merged into one. It
was normal for special events to be marked by lighting fires. We carry this
practice forward today with our Torch Light Processions and lights on Christmas
Trees and in public places.
role of Craddock Stone Circle;- One question often
asked is, how did the people of 2000BC know which was the shortest day of
the year? It just happens that one of very few winter solstice alignments on the
Moor is between the nearby Craddock Stone Circle (1 kilometre distant) and
Tregarrick Tor. There is even a raised embankment avenue joining the
Stone Circle to the Hurlers complex - problem solved.
Clearly the Hurlers were very important in the Bronze Age and
this should be more widely recognized and appreciated.
A summary of work carried out in the county appears in "The Hurlers an
Archaeological Assessment" published by the Historic Environment Dept of
The papers on precession and
the second on astronomy
on Bodmin Moor
the ages are on hold
at the moment.
find out more about my
attempt to spread the astronomy word
my link Canoe Africa and visit
our special Canoe Africa page. See
check out the reports
filed under IYA 2009.
dates are Sept 9th 2008 and Feb 12th 2009
- Thanks to Tammy Plotner.
ASTRONOMY TO CORNWALL