National Astronomy Week

March 1st to 8th is the UK’s National Astronomy Week, where Astronomical Societies up and down the country will be organising events to promote the study and enjoyment of the night skies.

At The York Astronomical Society we will be holding two events, both of which are open to the public.

The first is on Wednesday March 5th,  which is a public observing session on the concrete hardstanding half way along Knavesmire Road, opposite the end of Queen Victoria Street.  We will be there from 7pm onwards with a range of telescopes for the public to observe the night sky.  Given good weather, the Moon and Jupiter will be well placed to observe, along with many fainter objects such as the star clusters and the Great Orion Nebula. There is no charge for this event.

The second NAW event is one of our regular formal meetings, which will be held on Friday March 7th at 8pm in the Main Hall of the Priory Street Centre, off Micklegate.  The guest speaker is one of our own members, Mr Dave Armeson and he will be talking about the Lunar Reconnaissance Orbiter Mission to the Moon.  York AS members pay £1 at the door, and non members pay £2.50, with under 16′s going free.

We hope that you will be able to come along and join us at either, or both of these events.

http://www.astronomyweek.org.uk/

The Square Kilometre Array

Professor Melvin Hoare, Leeds University Department of Physics

Professor Hoare is one of the science advisors to possibly the most innovative astronomical instrument ever built.  The SKA, or Square Kilometre Array, is just that. It is a HUGE array of radio telescopes distributed over multiple countries, with the principal sites in South Africa and Australia, but involving nations representing 40% of the world’s population. The collecting area of the instrument is ultimately going to be equivalent to 1 square kilometre, but with a resolution of a telescope thousands of miles across. This will give it a resolution of 1arc second. 10 times the resolution of any such device currently in operation. The telescope may at first not look like the ones you are used to seeing, however its uses are endless and with applications in a vast and varied number of applications, from seeing way beyond the currently observable universe to detecting proto-planetary discs around neighbouring solar systems in our own galaxy. The latter is the principal area of research that Professor Hoare is leading up on the SKA. The SKA will be able to operate at a huge range of radio frequencies, from as low as 50 MHz right up to tens of GHz, which has a wavelength of only a few millimetres. It is these very short wavelengths that will allow Professor Hoare to detect dust and clumps of material ranging from pea-sized particles, rocks and boulders, right up to full-sized exoplanets. This will allow us to further develop our understanding of how the solar system and Earth were formed, as well as identify more potentially inhabitable planets in our galaxy. Some of his colleagues will also be able to detect organic materials in or around the galaxy, including amino acids, thought to be the principal building block for life. If we do indeed detect the presence of such organic compounds elsewhere in the universe then we can say that life is unlikely to be unique to us here on Earth.

One of the key challenges for the project is the immense amount of data generated from the thousands of linked-up (correlated, to give it its proper name) telescopes from around the world. When the telescope is running at full speed it will generate roughly 10 times the data that is currently generated by the entire internet!  Although the data will mostly be processed in real time, with the use of supercomputer technology archives will also be made. This is a huge technical challenge as even if most of the data is destroyed following real-time processing, there will still be hundreds of Petabytes of data generated every day the telescope is in operation. (1 Petabyte = 1015 Bytes, or One Thousand Terabytes) The supercomputer to process this will have the power of 1000 Million modern PCs.

As the Professor pointed out, this isn’t just a big telescope, it is one of the world’s largest engineering achievements that will undoubtedly produce some of the most ground-breaking discoveries in astronomy and physics in the 21st century.

Melvin Hoare at the York AS

We were privileged to have the Professor come and talk to us about this amazing project and hope he will return to keep us abreast of the telescope’s progress and, ultimately, the fruits of his labours.

For more information about Professor Hoare’s work and the SKA, visit: https://www.skatelescope.org and if you would like to contact the Professor:

m.g.hoare @ leeds.ac.uk

Supernova 2014J

A long time ago (about 12 million years) in a galaxy far, far away (about 12 million light years) a star exploded in a huge supernova.  Ever since that point in time, the light from that explosion has been spreading throughout the universe, and on January 21st 2014, that very same light finally reached our humble little corner of the cosmos.

As a result of the light reaching us we now get to see it, albeit 12 million years after the event itself.  It is seen as a very bright “new” star within the galaxy that we call Messier 82, or NGC3034 in the constellation of Ursa Major. Of course it’s not a new star at all – it was always there, but it’s now REALLY obvious!

A supernova occurs when a star reaches the end of its natural life, and no longer has enough fuel to create nuclear fusion.  When this happens the star implodes in on itself, causing a huge release of energy that we see as a supernova.

m82 gifAstronomers all over the world (well, those who can see far enough North to glimpse it) have been observing the supernova, measuring it, and taking photos of it. And here at The York Astronomical Society we are no different.

York AS member Gareth Verney took these two pictures that we have dissolved in and out for you.  These images were taken on January 9th and January 25th 2014, and show the obvious difference between “before” and “after”.  If you can’t spot it, SN2014J is the bright dot just left of centre!  Thanks for sharing this with us Gareth.

Build your own cheap camera drive

In May 2013, I published an article called “How to Photograph Star Trails” which explained amongst other things, the one fundamental issue that astronomers have to deal with when taking photos of the heavens – the fact that the Earth rotates, which makes everything appear to move across the sky.  That article encouraged you to embrace the fact that the stars move, and make a feature of it in your pictures.  However, once you have done that a few times, you will want to start taking pictures where the stars are NOT trailed in to lines.

Basically, in order to allow you to do long exposures of the night sky (around 5 to 10 minutes for example) you need to mount your camera on a device that rotates about the same axis as the Earth, at the same speed as the Earth, but in the opposite direction, so that the field of view in the camera remains the same throughout the exposure.

The first York AS meeting of 2014 was an informal evening, where members step up to do a 5 minute presentation on a subject of their own choice.  I decided to talk to the audience about the Haig mount, and how you can build your own.  A few people have asked for further details so please read on, dear reader.

2014-01-02 12.31.26My Barn Door MountThe “Barn Door Tracker” as it was then called, was first described in a Sky & Telescope article in 1975 by George Haig, hence the name “Haig Mount”.  It is a surprisingly simple piece of apparatus that can be made in a few hours with minimal equipment and only basic DIY tools.  The idea is that you have two pieces of wood that are hinged together.  The camera is mounted on the top piece and the centre pin of the hinge is pointed towards the Pole Star.  When in operation, the two pieces of wood are forced apart by a rotating bolt, or threaded rod, causing the camera mounted on it to slowly rotate at the Earth’s rotational speed.  There are many variations of the basic design, each improving the accuracy of the drive, but I will describe here the very simplest version of the design.

  • Cut two matching pieces of flat wood, approximately 300mm x 150mm x 15mm in size.  These will form the two halves of your “Barn Door”.  Join them along the short edge with a low-profile hinge (piano hinge is good if you have a piece), so that they open like a book.
  • An M6 Spiked NutYou will eventually need to drill a hole in the lower piece of wood, and thread it.  You can do this by inserting a spiked nut (pictured here) in to the wood itself.  Before drilling the hole, it is essential that you know exactly where to drill it, and that location is determined by the pitch of the thread of the bolt that you are using.  Here comes the maths bit:
  1. We are going to want to drive the two barn doors apart by rotating the bolt once every one minute
  2. We will assume for this description that the bolt being used is a metric M6 bolt, which has a pitch of 1mm.
  3. We know that the Earth rotates through 360 degrees in 24 hours (1440 minutes). This means that in just 1 minute, it rotates by 0.25 degrees. This is the rate at which we want the barn doors to open.
  4. Using trigonometry, we apply the formula A = O / tanθ, where “O” is the pitch of the thread (1mm), “θ” is the angle of opening (0.25 degrees) and “A” is the distance from the hingepin to the location of the centre of the bolt, and therefore where you should drill the hole.  So, A = 1 / tan0.25, which is 1 / 0.00436, which equals 229.18mm.  You now have your drilling measurement.Haig Mount Schematic
  • Drill the hole half way down the board (75mm from each edge) at a distance of 229.18mm from the centre of the hinge pin, and mount your M6 spiked nut, to make the hole threaded.
  • The M6 bolt you are using needs to be about 100mm in length. Cut a piece of wood or metal about 80mm x 20mm and drill a 6mm hole at one end of it.  Slide that on to your bolt and secure it at the head end using an M6 nut.  Your “driveshaft” now has a turning handle!
  • The Barn Door mount is now almost complete, but in order to make it usable as a camera platform there are two last things you need to do: 
  1. whit and ballYou will need to put a small aluminium plate on the underside of the bottom barn door, and that plate needs to have a 1/4 inch Whitworth screw threaded hole in it.  This is the universal standard tripod screw size.  You can buy whitworth taps for a few pounds from eBay etc, or ask around your friends – somebody might have one and make it up for you.
  2. Lastly you will need a ball and socket tripod head. This is the only “proper” piece of camera equipment you will need to buy.  They can cost anything from £10 upwards depending on how beefy you want it to be.  This needs to be mounted on the top barn door, and will allow your camera to point anywhere in the sky once the mount is set up.
  • Insert the M6 bolt “driving handle” in to the underside of the bottom barn door and wind it through until it just starts to open the barn doors.
  • Attach the whole mount on to the top of a sturdy tripod.
  • Take it out to your garden, and point the hinge pin towards Polaris, the Pole Star. (Approximate eye judgement is fine)
  • Mount your camera on the top of the ball and socket mount and point it towards your chosen subject.
  • Make your exposure and start winding the handle round at a rate of one revolution per minute.  To minimise the amount that you actually touch the mount during exposure, it is acceptable to wind the handle one quarter-turn every 15 seconds.  You can time this period either with a watch and a torch, or one neat way to do it in the dark is to get the quartz movement out of an old clock and hold it to your ear.  Every 15 ticks, move the handle around by a quarter.

This design of mount is by no means perfect, but it will allow you to guide your camera accurately for about 10 minutes, which under UK skies is probably plenty of time.  Here is an example of a photo taken with this type of mount.  As you can see, the stars themselves are sharp and untrailed, and it is the surrounding foreground that has trailed instead. Sadly this shot was NOT taken under UK skies, but in Australia instead, so sorry to build your hopes up!

Milky Way from Stockport

Keep checking back to this article in the coming few weeks, as I am intending to make a short film, demonstrating all of the above.  In the mean time if you have any questions, contact me at info@yorkastro.org.uk

Christmas Informal Night

pud2013 for The York AS was brought to a close in typical festive fashion last night when as usual we held our Christmas Informal Evening.  Not only that, but the evening marked our 900th meeting too, so celebrations all round!

York AS informal evenings are very simple.  There is no invited guest speaker, and members of the society are invited to step up and say a few words about whatever it is they want to, assuming that it’s vaguely astronomy themed.

Dave Armeson was up first, talking about some of the images he has taken over the last year with his 7″ Maksutov Telescope.  This was followed by Martin Whipp who gave a quick run down of a few things that are taking place in the sky during January 2014.  Up next was John Rowland who showed off his newest creation – a 5″ Dobsonian mounted Refractor.  John bought the optics, but made the actual telescope himself, making great savings by doing so.  This was followed by Rupert Powell, who spoke to us about the problems that astronomers face with dew on their camera and telescope equipment, and what can be done to combat it, again without breaking the bank. Lastly, two gentlemen in lab coats and top hats burst on to the stage and started blurting on about the Cooke Optical factory in Leicester, and what wonderful lenses they make for the cinematography industry.

cookesThese two fools go by the name of Thomas Cooke and his second son, Edwin Cooke, and they pride themselves in being York’s most knowledgeable deceased opticians!  Their presentation was followed by a short film knowledge quiz, and because it was in York and because it was Christmas, and because this presentation resembled a poorly-written pantomime, the prizes had to be Waggon Wheels!  Well done to all who got the questions right.

The night was brought to a very nice conclusion with the drawing of the Christmas raffle.  This had been running for a few weeks, and lots of prizes had been donated from various sources towards it.  I think at least a dozen members went away with a prize in their hands and a big smile on their face.  A lovely end to a wonderful year.

Amateur Time Lapse Photography

On the night of 2013 December 06, Mr Martin Whipp, FRAS presented his talk ‘Amateur Time Lapse Photography’. This was very different to our usual fayre of York AS presentations. Martin has for these last few years been working and perfecting his time-lapse techniques taking inspiration from various sources, and he has shown us a new look on the world.

In our day-to-day activities we see the world at a set speed (if there is one…) of time moving forward. Some things in the world we don’t see moving at any one moment, an yet move they do; for example hands on a clock, flowers, trees growing, clouds in the sky. By taking one picture every couple of seconds and ‘stitching’ these pictures together, another view on the world around us opens up. Clouds appear to scud across the sky, hands on the clock speed up, flowers and plants move before your eyes! And as for astronomy, aurora comes alive, the Sun and Moon move across the sky rising and setting, stars show their circumpolar motion and much more.

Limetree South

Martin reminded me of ‘The Time Traveller’ from H.G Wells’ ‘The Time Machine’ and like a latter-day Time Traveller he bewitched the audience so much that the evening flew by, and like that traveller Martin had a great display of equipment he has built (some with Roo Powell’s help).

Martin, was your talk really about a hour-and-a-half? I for one really enjoyed it and I know the audience did too…

A Report from the York AS Observatory

On the evenings of 2013 November 29 – 30 York AS Members observed perfectly clear skies considering the proximity to York. On Friday evening Dave Armason and Malcolm Muncaster had their Skywatchers set up.

I for one was impressed at the views of Jupiter, 40mm eyepiece on Double Cluster in Perseus and M15 Globular Cluster in Pegasus through a 18mm were beautifully resolved. We also saw Gamma Andromedae, a beautiful double star in Andromeda with an orange primary and a turquoise secondary.  The Orion Nebula through a 26mm Panaview gave a wide field of view and showed structure.  Close in with an 18mm orthoscopic gave more intricate structure and mottled clumps and dust around ‘The Fishes Mouth’ and Trapezium.

Jupiter was stunning. You could have seen four belts and Martin Whipp saw Jupiter’s moons as distinct disks for the first time, and concluded that Io was the innermost moon looking at the view. The observation session was finished on Jupiter during ‘localised seeing conditions’ (Certain individuals know why! Dave’s words not mine).

I still say the 1970′s Orthoscopic eyepieces are far superior to any modern eyepieces.

On the evening of the 30th, we had the first of what we hope to be a more serious observing session, one where white light torches and car headlights are banned between 20:00 and 23:00 to permit imagers a degree of light pollution free sky. One thing amused me, some members have invested a lot of time and money and effort in some very impressive equipment but were faced with no amount of trouble and yet one of the younger members working to a shoe string budget and second hand equipment captured some amazing images of The Great Orion Nebula. I sincerely hope I didn’t tread on any toes but it just made me smile…  Well done Harry, looking forward to seeing your results and best of luck with the Spectroscopy and A-levels!

Sutton Bank Star Party 2013

The evening of November 2nd saw a group of York AS members meeting at the North Yorkshire Moors visitors centre at the top of Sutton Bank. We were hoping to show the public the beautiful dark skies from up there. Sadly, the weather had other plans, and thunder, lightning, rain, wind and even snow meant that we had to run the show from inside the visitors centre instead.

Visitors at Sutton BankWe had a good selection of instruments, including Alan’s impressive looking 16″ Dobsonian telescope, a multitude of binoculars, right down to my “Che-apo” scope!

Dave gave a very good talk consisting of a tour through the solar system.  I followed that with a bit about the ISS and meteors.

We had over 30 visitors, which given the weather and it being the Saturday nearest to bonfire night wasn’t bad at all.  They took part in our raffle, bought one or two books too, and everyone seemed to enjoy themselves.  The general tone of the feedback we received was “When are you doing it again”?

Well – this coming Wednesday we are back out on the York Knavesmire!  See you there!

In the Museum Night Garden

Last night, October 30th saw a great number of the public meeting with members of the York AS in the Hospitium in Yorkshire Museum Gardens. The Museum was hosting an event called “In the Museum Night Garden”.

Scopes in the HospitiumMalcolm, Alan, Jane and Laura had telescopes on display while Dave had a rolling presentation of selected astronomy and spaceflight pictures on a screen. MD occasionally showed some short presentations on the ISS and shooting stars. Dave was joined by Rachel and other YAS members and did excellent work selling planispheres and books and made a staggering £40 for YAS funds. We were also joined by Sam and her two daughters who both had made some small ‘bouncy balls’ at another stall and they looked surprisingly like Jupiter!

A group from the university had a blow up Planetarium, which was great fun. Other groups where showing insects, painting faces, putting on space suits and poking around in owl pellets looking for bones! Although it was cloudy a good time was had by all.  We’re looking forward to the next one in February!