Treak and Blue John

View across the Hope Valley Castleton Derbyshire from above the entrance to Treak Cliff Cavern

Earlier in August, Toot, the Family Bimbar and I visited the Treak Cliff Cavern in Derbyshire. We had an excellent tour of the cavern led by a knowledgeable and funny guide.  He also shared my interest in Banjos and Bluegrass picking!

The Treak Cliff Cavern was started as a mine over three hundred years ago and during more recent mining operations an entrance to naturally occurring limestone caverns was found.  The caverns are a major tourist attraction but Blue John is still mined at Treak outside of the main tourist season.

Blue John is a blue and orange banded fluorite mineral.  It is extremely decorative and has been used for jewelry probably since Roman times. The use of Blue John for the manufacture of cups, bowls and  tops for high class furniture was particularly popular with the gentry in the 18th and 19th centuries.  There are magnificent examples of worked and turned Blue John artifacts at the nearby home of the Duke of Devonshire, Chatsworth House.  Blue John is not easily worked as it contains many potential lines of fracture, so in order to turn a Blue John bowl, the mined mineral has first to be impregnated with resin.

Blue John Vein

The mineral veins of Blue John were formed in the Derbyshire Peak District during the Carboniferous Period.  The minerals were deposited in veins by layers of crystals precipitating from hot fluids coating the walls of fractures, caves, and other cavities. The Blue John Fluorite is often found associated with Dog Tooth Calcite Crystals and fossil crinoidal lilies.

I purchased a piece of Blue John with an integral section of crinoid lily stem from the Treak Cavern Shop.

My Purchase

The Treak Cliff Cavern is also famous for its coloured flowstone, stalactites and stalagmites.  For those that cannot remember, stalactites hang down and stalagmites thrust up from the ground.  It is generally accepted that Treak Cliff Cavern boasts the finest stalactites in the Peak District.  Nearby the Treak Cliff Cavern are the Blue John Cavern and the Speedwell Lead Mine but in my view Treak is the best to visit.

Multi-coloured flowstone in Aladdins Cave Treak

Stalactites, Stalagmites and Flowstone Treak

The Dream Cave Treak

For more information:
www.bluejohnstone.com

Credits: Treak Cliff Cavern and Wikipedia

Mars Update

Composite Image taken by 'Curiosity' at the end of July 2013 enroute to its destination Mount Sharp
Credit: NASA/JPL-Caltech/Malin Space Science Systems

From the United Kingdom and in September, Mars is visible at magnitude 1.6 as a 4 arc second disc low in the Eastern sky during the early hours of the morning. 

Currently, NASA has two operational robotic explorers active on the surface of Mars; the venerable 'Opportunity' which left earth some ten years ago and 'Curiosity' which this month completed its first year in Gale Crater.

Superimposed image of Opportunity on the rim of Victoria Crater
credit: NASA/JPL/Cornell

'Curiosity' having tested its autonomous drive, drilling and chemical analysis systems, is now making its way across Gale Crater towards Mount Sharp where it hopes to discover and analyze rocks laid down over millenia. 'Curiosity's' first year on the surface of Mars has been an engineering and scientific success of enormous significance.

Three images taken three seconds apart by 'Curiosity' looking up to
witness the annular eclipse of the sun by 'Phobos' the larger of the
two moons captured by Mars
credit: NASA/JPL-Caltech/Malin Space Science Systems
/Texas A&M Univ.

Mars has two moons 'Phobos and Deimos'. They are quite tiny, unobservable in amateur telescopes, and considered to be asteroids which ventured too close to Mars and were captured by its gravity.

'Opportunity' has completed over 3,400 days on the surface of Mars, well exceeding its operational parameters and scientific goals.  It is currently investigating the boundary geology of 'Solander Point', a raised area on the rim of Endeavour Crater.  The NASA engineers plan to drive the robot onto a North facing slope where it will endure the Martian Winter with its solar panels orientated to best exploit  low angled sunlight.

Opportunity

Curiosity

http://www.nasa.gov/mission_pages/msl/index.html#.Uh_QM9KsiSp
http://marsrover.nasa.gov/gallery/press/opportunity/20130814a.html

The Comma Butterfly

A Comma Butterfly on our fig bush.

A rare visitor to our garden, a Comma  Butterfly.

The Comma (Polygonia c-album) is a species of butterfly belonging to the family Nymphalidae. Its irregular wing edges are characteristic of the Polygonia genus, which is why they are commonly called angle wings. It is found in northern Africa and across Europe from Portugal through Asia as far as Japan. Its dorsal wings are colourful but its underside has a pattern that camouflages it when its wings are held together.

Polygonia c-album has a wingspan of about 45 millimetres (1.8 in). The underside of the wings of this butterfly are a dull brown colour, with a small white 'C' shaped marking resembling a comma (hence the common name). The wings have a distinctive ragged edge, apparently a cryptic form as the butterfly resembles a fallen leaf.

Credits Wikipedia

The ISS over Suffolk

The International Space Station
passing over our backyard on the 18th of August 2013
(the line at the bottom centre of the image represents
the path of the ISS during an exposure of 60 seconds)

I took the image using a tripod mounted Lumix compact camera at F2.8 using the camera's 'Starry Night' setting. The passage of the ISS can be seen  under the Summer Triangle asterism formed by the stars; Deneb, Vega and Altair. The constellation Vulpecula, The Little Fox, can be seen at the centre of the 'Triangle'. The red tinge to the clouds is caused by 'light pollution', the bane of the urban astronomer!

I really enjoy watching the ISS passing over our garden and I am always surprised at how bright it is!

The ISS orbits the Earth at 7.71 Km/sec some 370 km above us.

For more information see:
http://www.nasa.gov/mission_pages/station/main/index.html#.UhSuk9KsiSo

Credts: NASA

The Boon Gallery, Suffolk

The Boon Collection

The Boon Gallery, in Oulton Broad Suffolk, is currently exhibiting a definitive collection of iconic works by the Oxfordshire sister and brother painters, Pixie and Archie Boon.  Their works include the enigmatic paintings:

Fish in a shoebox by Pixie Boon

Random Bloke in a Wood by Archie Boon

Nova in Delphinus August 2013

Enlargement of the image captured from our Backyard
 using a tripod mounted Canon DSLR Camera

A 'Nova' is an unimaginably violent explosion on a white dwarf star which is part of a binary star system.


A white dwarf is a stellar remnant, the leftover core from a main sequence star not sufficiently massive to become a neutron star or black hole when, at the end of its life, it ran out of fusible material.


If the white dwarf is sufficiently close to its binary partner for it to steal hydrogen and helium gas from its surface, fuel for a nuclear explosion builds up.  When the captured hydrogen and helium sitting on the surface of the white dwarf reaches a critical pressure and temperature, 20 million degrees Kelvin, nuclear fusion occurs and the star is seen to brighten as a Nova.




A Nova should not be confused with a Supernova, in a Nova the white dwarf is not destroyed but instead, as viewed from Earth, is seen to brighten and then dim over a period of time.  A white dwarf can Nova a number of times. A supernova is a much rarer event, happening only once at the end of a massive star's life.

Artist's impression of a Binary Star System in which a White Dwarf
 is accreting material from the outer atmosphere of a bloated red star.
(Credit Wikipedia)

Stacked image taken from our Backyard of an area of sky with the Milky Way running through the Constellations Cygnus and Aquila. The constellation Delphinus, the Dolphin, is located bottom centre. The Nova is highlighted in yellow.

The Nova can be seen with binoculars, so if its a clear night where you are, why not go out and see if you can find it?

The Nova was discovered in August by the Japanese amateur astronomer Koichi Itagaki. 

Is there anybody out there?

The Andromeda Galaxy M31 photographed from our
backyard in the early hours of the morning August 2nd 2013
One trillion stars 2.5 million light years from Earth.

Due to an unusual outbreak of good weather, 'The Cabine' has seen an outburst of  astronomy focussed action.  Clear Skies everyone!

When its late and quiet in our garden and as I look out into the the depths of space, I often wonder if; there is an alien version of me, in a garden, on a planet orbiting a star, long ago or in the future and very far away, looking through; his, her or its telescope and wondering at my improbable existence?

Between midnight and three in the morning on the 2nd August, the weather was absolutely beautiful and the sky transparent.  I watched the International Space Station pass serenely over our garden, it's quite something to see  and far brighter than you would expect.

My first imaging target was Messier 92, a globular star cluster in the constellation Hercules.  M92 tends to get passed over because it is the same part of the sky as M13 The Great Globular Cluster in Hercules and because it is slightly more difficult to image.

My second target was M31 the Andromeda Galaxy.  In the past I have been able to image its core but not its more nebulous spiral arms.  I'm quite pleased with the above image but I'm sure I can do better with a guided series of exposures, watch this space!

At three o'clock in the morning, the crescent Moon climbed above my garden hedge and I tripped off to bed a happy man!

M92 Globular star cluster 26,700 light years from
 our solar system and some 14 billion years old.
(enlargement below)

The photographs were taken with a Canon 400D DSLR camera attached to my Meade 127mm APO refractor operating at F7.5, mounted on a NEQ6 Pro mount.  Multi - light, flat and dark frames were stacked using DeepSkyStacker and final processing applied using APS.

Credits: Wikipedia

Ooh what a lovely big one!

My image shows the rear end or tail of
 the constellation Cygnus the Swan. 

It would be quite rude to leave the constellation Cygnus without mentioning Alpha Cygnus otherwise known as Deneb. Deneb can be seen currently riding high in the eastern sky from about 10.00pm British Summer time.

Deneb, along with Vega in the constellation Lyra and Altair in the constellation Aquila, form the asterism known as the Summer Triangle. The Summer Triangle is very easy to identify if you look south to east, as the three stars Deneb, Vega and Lyra are very bright and form its three corner points.  If you have a clear night, why not try to identify these three stars?

Deneb is a blue-white supergiant star, the nineteenth brightest star in the night sky, estimated to be between 54,000 and 196,000 times more luminous than our Sun.  It is thought to be 26,000 light years distant from our Solar System.  Deneb is a big star with a diameter some 100-200 times and a mass some twenty times that of the Sun.

All in all Deneb is 'a big one' alright but losing mass through its powerful solar wind at a prodigious rate, approximately 100,000 times faster than our Sun.  At 8500 degrees Kelvin, Deneb's surface temperature is also much hotter than the Sun .  Deneb has finished fusing hydrogen in its core and after a relatively brief existence as a red supergiant and in a few million years time, will explode in a catastrophic core collapse supernova.  That will be a big one too!

Hertzsprung-Russell Diagram

You can see Deneb at the top of the Hertzsprung-Russell Diagram.  As Deneb ages it will move to the right following a path taken before it by the star Betelgeuse in the constellation Orion.

Betelgeuse will be visible from the UK in late autumn, winter and early spring.

Credits:Wikipedia, NASA, ESA, Flickr and Astrometry Solver.

The Summer Triangle