Nordurljuos

Aurora Borealis - Tromso Norway - Canon 400D DSLR =18-55mm EOS lens at F3.5, f=18mm. ISO 1600 - Archie Mendes 2011

“Galileo Galilei (1564-1642) saw the ‘Northern Lights’ from Italy and called them ‘Boreale Aurora’ or ‘dawn of the north’ this was because from Italy the lights were usually seen as red and always to the north.  In the far north the aurora are not associated with dawn, they can appear at any time of night, and are usually yellow-green.  In 1621, the well known astronomer Pierre Gassendi - observing the ‘Northern Lights’ from Paris, turned Galileo’s words about face and called them ‘Aurora Borealis’.

The Aurora Borealis or Northern Lights have intrigued mankind for millennia.  Aristotle described the Aurora as ‘Meteron’ which roughly translates as ‘something appearing in the air’ and my favourite- the allegoric description ‘Capre Saltanti’ translating as ‘jumping goats’.  Sir Edmund Halley (1656-1742) believed they were controlled by the Earth’s magnetic field while the French scientist – Jean-Jacques d'Ortous de Mairan (1678 –1719) claimed they were the result of interactions between the atmospheres of the Sun and Earth.  

From a book written in AD1250 and albeit after the end of The Viking Age (AD800 – AD1100), the ‘Old Norse’ word for the ‘Aurora Borealis’ is ‘norðrljós’.  The pagan Vikings believed the ‘Northern Lights’ were the gateway to Asgard the home of their gods.

'Bivrost' - The bridge between earth and sky or 'reflections of shoals of herring'? - Reykavik 2017 - Canon 600d DSLR EOS 18-55 lens at F3.5, f=18mm. ISO 1600, 5 sec exp.- Kurt Thrust 2017

Following in the footsteps of: F.C. Meyer (1697-1729), Jean Baptist Biot (1774-1862), Christopher Hansteen (1784-1873), Anders Jonas Angstrom (1814-1874), Carl Fredric Fearnly (1818-1890) and Karl Selim  Lemstrom (1838-1904), the Swedish scholar Kristian Olaf Birkeland (1867-1917) promoted the idea that the ‘Northern Lights’ were formed when high energy, so called cathode rays’ that were emitted from the sun were caught in the earth’s magnetic field and forced towards the earth’s atmosphere in the polar regions. He believed that these ‘cathode rays’ or electrons as we now call them, and the atoms and molecules of atmospheric gases interact to create the aurora in two luminous rings one around each pole. Birkeland was so convinced by this idea that as a demonstration experiment, he created a chamber from 10 cm. thick glass from which was evacuated as much air as was possible with the technology available 100 years ago. Inside the chamber was a centrally suspended metal sphere containing an electro-magnet.  A high electric charge was established between the sphere and a cathode positioned in one corner of the chamber. The electrons emitted from the cathode were caught in the magnetic field around the sphere and forced to move towards the surface in the polar regions of the sphere. Through adjustments of the voltage and the electro magnet he was able to create two parallel rings around the sphere, just like the aurora and as his theory predicted.  When I first saw the Aurora from Norway, a working model of his apparatus was on display in the Science Museum at Tromso.

The driving force behind the aurora is the sun. The 'lights' are created by the interaction of the solar wind with the earth's magnetic field and the atoms of gas in the upper atmosphere.  When the sun is active – lots of sunspots and coronal eruptions of charged particles, the aurora puts on dramatic displays of moving luminosity and colour. The green and red colours are associated with excited oxygen atoms and blue with excited nitrogen.

 

Aurora Borealis - Tromso Norway - Canon 400D DSLR =18-55mm EOS lens at F3.5, f=18mm. ISO 1600 - Archie Mendes 2011

The Sami peoples, who herd their reindeer under Scandinavian skies, have more than one word in their language for the aurora  but the most commonly used is ‘guovsahas’- meaning ‘the audible lights’. Having seen them ‘dance’ across the sky I swear I also heard the flutter of the changing colours. There is however no real evidence that the aurora creates sound waves.  As the ‘Northern Lights’ occur at an average height of 105 km above the surface of the earth there is probably insufficient air to enable sound waves to form.

My favourite explanation for the ‘Northern Lights’  may be found in Danish Folklore where it was said that the lights were the result of wild swans flying too far to the north and becoming frozen in ice. Each time they lifted their wings in an attempt to free themselves, the reflections from their wings caused the ‘Northern Lights’ to shine”.  Archie Mendes - visiting astrophysicist at the Jodrell Plank Observatory.

For a modern easy to read scientific explanation of the aurora folow the link to David P Stern's paper:

https://www-spof.gsfc.nasa.gov/Education/aurora.htm

Aurora Borealis

Aurora Borealis - The Northern Lights - Over Reykjavik Harbour - October 2017 - Annimated still images -  Canon 600D DSLR - EFS 18-55 Lens F3.5 f=18mm 10x5 sec exposures at ISO1600

"After a few days in Reykjavik the skies cleared and the 'Northern Lights' made an appearance over the cold waters at the junction of the North Atlantic and the Arctic Oceans. " Kurt Thrust current Director of the Jodrell Plank Observatory.

On the Beach

Last night the Aurora Borealis over Corton Beach near Lowestoft - a green glow under the tail of the Great Bear - image by Ronald Clump - CEO - Jodrell Plank Observatory.

"Mr. Clump has been enjoying quite a lot of his 'me time' on Corton Beach .  In late autumn and winter and after about 19:00 UT, the beach car park is a readily accessible 'Dark Site' . No wonder our new CEO has been spending a lot of time there!  Last night the Aurora Amber Alert was actioned and fortuitously Ronald found himself on the carpark with a camera to hand. The above super image taken with a tripod mounted Canon 600D DSLR -1x 20 second at ISO1600 - F3.5 and f=18 - shows the tell-tale colours of excited nitrogen atoms - the auroral glow of -'green and magenta'.

Whilst he was there, he also captured some wonderful images of the Milky Way running through the constellations Perseus and Cassiopeia. The tiny meteor and the Andromeda Galaxy are bonus features." - Kurt Thrust current Director of the Jodrell Plank Observatory.

The Milky Way in October - looking east out across the North Sea - 600D DSLR 6x20sec exposures at ISO3200 F3.5 and f=18. - Photography Ronald Clump. Image processing by Pip Stakkert

The Deerlick Group and NGC7331

NGC7331 and the Deerlick group of galaxies in the constellation Pegasus - Combined image PIRATE and COAST automatic autonomous telescopes - telescope.org - Open University - image by Pip Stakkert

"NGC7331 is an unbarred spiral galaxy approximately 40 million light years distant located in the constellation Pegasus. It is the brightest member of the NGC7331 group of galaxies and is approximately the same size as our Milky Way galaxy. The other members are lenticular or unbarred spirals, NGC7335 and 7336, the barred spiral galaxy NGC 7337 and the elliptical galaxy NGC 7340. These galaxies are at distances of approximately 332, 365, 348 and 294 million light years, respectively.  NGC 7331 is therefore unlikely to be interacting gravitationally with these galaxies. It is thought that NGC7331 has been tidally disrupted by a past encounter with Stephan's Quintet of galaxies which are relatively nearby".- Kurt Thrust current Director of the Jodrell Plank Observatory"

Annotated image- Archie Mendes

Credit: Wikipedia 

Superluminous Supernova - SN2017 egm

Superluminous Supernova SN2017 egm in the barred spiral galaxy NGC 3191 - PIRATE ART telescope-telescope.org - Open University. Image by Pip Stakkert

"Superluminous supernova are usually found in metal poor galaxies, so this superluminous supernova in a metal rich barred spiral galaxy is unusual to say the least. Superluminous supernova are typically 10 times more luminous than other supernovae.  A number of models for the conditions that may produce a SLSN exist:

• Collapsar Model: The collapse of a rotating star giving rise to stellar mass black hole with the production of relatavistic jets.
• Circumstellar material Model:  An initial normal supernova explosion meets dense nebular material or dust close to the star, the shockwave converts kinetic energy efficiently into visible radiation thus increasing luminosity and duration of the supernova.
• Magnetar energy release Model: A magnetar is a type of neutron star with an extremely powerful magnetic field. Models of the creation and subsequent spin down of a magnetar yield much higher luminosities than regular supernova.
• Other Models: There are models for SLSN explosions which are produced from binary systems, white dwarf or neutron stars in unusual arrangements or undergoing mergers.

SN2017 egm is a Type 1 supernova, first observed by the Gaia Satellite in May 2017, and light curves obtained from observations have been used and found to be consistent with a Magnetar central engine model. The supernova was discovered in the barred spiral galaxy NGC3191 which is estimated to be 420 million light years distant. The measured magnitude of the supernova is 14.5 and at its distance, its calculated absolute magnitude is -21.1, which in luminosity terms is comparable to the output of our entire Milky Way galaxy.  It turns out that SN2017 egm is the closest hydrogen poor superluminous supernova ever found. This type of 'hypernova' which create millesecond spinning neutron stars are thought to be one of the progenitors of long duration gamma ray bursts - LRGBs.

Closer to home, may I take this opportunity to extend our congratulations to our Instrumentation Engineer- Jolene McSquint and our Facilities Manager- May Fleming who this week surprised the Jodrell Plank Observatory Team by announcing their engagement".  Kurt Thrust- current Director of the Jodrell Plank Observatory.


Credits: Open University, Wikipedia and IRIDA Observatory

Leapin and hoppin' on a moonshadow

Two pane composite image of the full moon taken just after midnight on the 6th of October 2017- 66mm. ED refractor piggy-backed on the 127mm. refractor- QHY5-11 colour planetary camera

" The weather improved for a few hours last night just enough for us to be able to capture the 'full Moon'. We tried to image the planet Neptune but the seeing was not good enough for us to capture a steady image. Pip Stakkert has used software in the second image, to enhance the surface albedo and reflect the changes in surface mineralogy." - Kurt Thust - current Director of the Jodrell Plank Observatory.

Two pane composite image of the full moon showing enhanced surface albedo based on 12 colour palette

“ Like Elvis - a known resident, I have always been inspired by the full moon and one day, hopefully very soon, we will all be able to go there on scheduled flights.  Down here on planet Earth however, things have not been going so well. Our on-going dispute with our neighbour, 'quantum cat-man', shows no improvement. He refuses to pay for 'the wall' or contribute towards its cost even though Waffles Construction provided a very competitive estimate.  Shocking rumours have also been going around the Observatory that Lenny Brezhnev -owner of the Beccles Softball and Rounders Club -'Beccles Badgers'  and former 'pitcher' for ‘Chicken Kiev SBC’, used his formidable resources to influence the trustees of the Jodrell Plank Observatory in my appointment as CEO. This is a shocking lie put about by little people jealous of my considerable charm, good looks, money and across the board entrepreneurial spirit.  I have launched an investigation into this slur on my character and I am sure Mr Schrödinger or his wayward pussy will be found to be behind this” – Ronald Clump – CEO Jodrell Plank Observatory.

Galactic Dust Lanes

Messier 63, The Sunflower Galaxy - Autonomous Robotic Telescope - PIRATE, Open University. Pip Stakkert

"The weather over the Jodrell Plank Observatory remains poor with strong winds and rain lashing those foolish enough to venture forth into the 'great outdoors'. Pip however has spent his free time wisely, using data collected from the remotely accessible PIRATE telescope on Mount Teide in the Canary Islands, to produce this image of the beautiful Sunflower Galaxy viewed amongst the stars of the constellation Canes Venatici. In reality the galaxy is much further away than these Milky Way stars at approximately 27 million light years distant from our Solar System. The spiral arms of the galaxy containing millions of stars can be seen clearly with dark dust lanes creating a visual 3-dimensional effect. The incredible amounts of gas and dust that make up these islands of matter in the universe have been brought together and set spinning by the the all pervading force of gravity. Each and every active star that we can see on any clear night is at some point in a gigantic nuclear tussle with gravity which will eventually lead to metamorphosis. When this will happen and what the star will become depends only upon the it's initial mass. Gravity will eventually overwhelm the radiative pressure of nuclear fusion at it's core and then it will commence a one way process which will end in the creation of a 'white dwarf star', a 'neutron star' or a 'back hole'." -  Kurt Thrust current Director of the Jodrell Plank Obsevatory.

Messier 31, The Andromeda Galaxy - a dark dust lane seen against the galaxy's central core - Autonomous Robotic Telescope - PIRATE, Open University. Pip Stakkert