Stargazey Pie June 2006
Flaming June, eh? It was certainly hot enough on the 6th when we had the June meeting of the Highlands Astronomical Society. A hot sunny day followed by a HAS meeting- what could be better? In keeping with the weather the main talk was about the Aurora and how it is caused by events on (and in) the Sun. There were some major announcements about the new observatory project too, and three breakout groups that took place after the tea-break. As usual, the meeting started with the notices being read by Chairwoman Pauline.
- Thanks! Thanks were levelled at the three speakers last month: Rhona Fraser, Donald Boyd and Arthur Milnes. Rhona talked about her experiences on a solar eclipse viewing trip to Libya. Pauline has a newsletter from the Isle of Wight Astronomical Society, and one of their members has written a report of his experiences- probably on the very same trip! If you would like to compare notes between Rhona’s experiences and that of the other observer, please contact Pauline to see the newsletter or get more details.
- Abriachan Wood Henge. HAS have made contact with Abriachan Forest Trust about the proposed wood henge. It seems that they have the people to build the henge and just require our input for the design and astronomical data. David Hughes is our man in the woods, and is liaising between the trust and HAS to keep this project growing.
- Letter from America. Thinking of going to Philadelphia in August? If you’re going to be there from the 11th to 13th you could attend an astro-imaging conference. No further details here, but if you’re interested just ask Pat Williams. ‘Roving Reporter’ status for those interested could be a possibility, but if you expect the Society to pay for your flight you may be waiting a while…
- Are you a Practical Astronomer? A new astronomy magazine has been launched- Practical Astronomer. As the title suggests, this magazine is aimed at the hands-on astronomical observer, and features reviews of equipment, hints and tips on how to observe better, and how to enjoy using your astronomical equipment. There will be competitions too, with items that have been reviewed offered as prizes. Latest news from Ian Brantingham, who has a copy, is that the magazine will only be available by subscription, so no use trawling through Smiths for this one. Pauline has promised to contact the publisher to see about HAS receiving a complimentary copy to be assessed by the membership! Check out the Practical Astronomer website for more details, including some downloadable samples.
- FAS Convention. The Federation of Astronomical Societies will be holding their convention on 30th September at the Birmingham and Midland Institute in Birmingham. Speakers will include Scotland’s Astronomer Royal, Professor John Brown, Dr Allan Chapman, Dr Somak Raychaudhury and Dr David Whitehouse. There will also be other exhibitors, and entrance fee will be £12 on the door or £10 if pre-booked. Email firstname.lastname@example.org or phone 01684 773256 for more details.
An Observatory Update
After the notices, we had a thorough update about the new observatory project from Pauline and Maarten. Pauline started off by explaining that recent meetings with Alexander Bennett of the National Trust for Scotland had gone extremely well, and he was happy with the most recent proposals. The new observatory is being designed to blend in with the new visitor centre at the Culloden battlefield, and will be situated some 200 yards or so away from the main centre.
The updated plans were on display on the wall, and it was obvious even at a cursory glance that the new observatory will incorporate a traditional dome for housing the telescope! The particular one decided on is a 9ft diameter dome supplied by Pulsar Optical in England. A great advantage of this is that the suppliers will actually travel up with the dome and install it for us when it is needed! Pauline also at this point expressed the Society’s thanks to Rob Nuttall, who has put many hours of work into producing the plans.
One of the conditions when acquiring funding is that building quotes be supplied by several companies or individuals so that they may be judged on their costs and merits. Three firms have been approached; one owned by Ian Grant, who is also a friend of Arthur Milnes, BMJ Builders and Morrisons Construction. Since Morrisons will be on site building the Visitor Centre, and will be using the very same materials to build the centre, it seemed logical to ask them for a quote, and we have fingers crossed that if theirs was acceptable it would perhaps make the whole job a bit easier simply by them being already involved.
Pauline finished on a high- we have got some money! Our recent funding application to Highland 2007 was successful, and we have been awarded nearly £25,000 to put towards the project! This is incredible news, and is a real boost to moral. It shows that things have really started to take shape, and it will not be too much longer before Inverness has an observatory again!
This was a point taken up by Maarten after Pauline had finished speaking (and bouncing around with excitement), as it is a major consideration for further funding applications, especially the one to the Inverness and Nairn Enterprise people, who consider a new observatory will be a major boost to the area and something to be really proud of.
Maarten also showed some computer images of the new design in 3D, and explained some of the features and design decisions that have been made. It was very impressive to see the images of our future observatory brought home to us like that, and I have put the images on the Spacegazer site for you to enjoy. Just click here to see the latest!
The main features of the observatory design are listed below:
- 6m x 4m heated control room with computer desk, internet access and disabled toilet
- Raised (timber) platform for dome
- 3m diameter (motor driven) Pulsar Dome
- 14” Ritchey Chretien Cassegrain type telescope with full computer pointing and collimation
- Large concrete pier, going through timber deck
- 10m x 6m grass covered observation area with 1.8m high wind proof fence
- Mains water and electricity from VC (metered)
It was also pointed out that the new visitor centre and surrounding area is planned to have very astronomy-friendly lighting. Mr Bennett has even gone so far as to insist on low level down-lighters, and to block plans for a roundabout with heavy lighting from being built! This all sounds extremely promising and exciting. We are all keeping our fingers crossed that our current roll of good fortune continues. If you have any questions or suggestions regarding the new observatory, please address them to Pauline, Maarten, Bill Jappy, Arthur Milnes, Rob Nuttall or myself.
The Main Event
The Aurora by Ian Brantingham, SIGMA
Ian is an ex-RAF-fer, having been regularly airborne for 35 years, and is a keen observer and Secretary as well as member of SIGMA, Moray’s Astronomy Club. He is also the Auroral Director of the Society for Popular Astronomy, and can be contacted about all things auroral using this email link.
Ian started by looking at the history of aurorae. They have been noticed and observed for a long time, going back to at least 567bc. In medieval times the flashing sheets of light in the sky were thought to be the battles of deities in the heavens. Such superstitions were understandable for the times, and continued until the age of science. In the 18th century Edmund Halley and Jean-Jacques de Martin began to apply scientific principles, and it was first proposed that there may be a correlation between sunspot activity and aurorae. In 1859 this relationship was confirmed when the English astronomer Richard Carrington discovered a solar flare while observing sunspots by telescopic projection on September 1st. On the night of September 2nd there was a spectacular aurora and the association was well and truly confirmed.
Ian described the aurorae as smoke from the big fire of the Sun. He went on to explain just how large the Sun is in solar system terms by tearing up several pages of the Press and Journal. I suspect he enjoyed it. He demonstrated that of the total mass of the solar system, 99.86% of it belongs to the Sun, with the remaining 0.14% consisting of everything else in the solar system. Of that 0.14%, Jupiter has the largest share.
Having established that the Sun is quite big, the next step was to see why aurorae occur- what happens in the Sun to make them happen. Some Chemistry ensued, with emphasis placed on how atoms within the Sun are affected by gravity, compressed and heated up to 15 million degrees or so, when nuclear fusion then occurs, releasing energy.
The radiation released travels from the core of the Sun to the photosphere, but it takes a long time to do so; 10,000 to 1,000,000 years depending which sources you read! As the Sun’s interior rotates more slowly than the exterior, electromagnetic fields are produced, which cause sunspots to occur. It has been proven that the more sunspots there are the more likely it is that an aurora will occur. This is because sunspots indicate solar activity, and solar activity means increased energy releases in the form of coronal mass ejections, solar flares or solar wind.
High energy ejections and flares can be quite cataclysmic events, and if it were not for the protection of the Earth’s magnetosphere we would all be in very serious danger from the high energy radiation (including X-rays) that would impact us. Even as it is, large flares can easily affect our electronic equipment, resulting in events like the electrical blackout in Canada of 1989. With so much of society depending on electronic equipment now, a really big flare could be disastrous.
After discussing the science behind why aurorae happen, Ian went on to talk about how they manifest themselves to us Earthly observers. Of course, images were shown of one of the most outstanding series of aurorae in recent years, which took place in October and November 2003. (See the Spacegazer Image Gallery for pictures of these). The typical sheets or curtains of an auroral display were quite obvious, and Ian mentioned the different colours that are apparent and how they are caused by the gases in our atmosphere being excited by the emissions from the Sun. The electrons emitted by solar flares and coronal mass ejections flow down the Earth’s electromagnetic field lines, exciting the atmosphere as they go. At higher altitudes (>150 miles) Nitrogen is affected, giving a red tinge to the aurora, and at lower altitudes (50-150 miles) the characteristic green of ionized oxygen is seen.
Some people (including local member Christine Clifford) claim to have ‘heard’ the aurorae! Ian explained that this can possibly be caused by objects such as trees or other objects in the vicinity of the observer, or even their own bodies, picking up audio-frequency electromagnetic waves and converting them to acoustic waves. In effect, our own body could act as an antenna tuned into the radio emissions of the aurora!
A recent discovery is the strange ‘Black Aurora’. These show themselves as sharply defined areas of blackness against the normal colourful auroral displays, and last for just a few minutes. Research using satellites has shown that they are actually areas where a kind of ‘anti-aurora’ is formed. They form in areas where there are holes in the ionosphere, which is the part of the atmosphere where aurorae are created. Instead of incoming electrons acting on the atmospheric particles, the atmospheric particles are actually being sucked out into space, where they form huge electrically charged ‘towers’ that can extend up to 20,000 km into space.
Other strange aspects of aurorae that Ian discussed were the aurorae that occur on other worlds- Jupiter, Saturn and Mars. He showed a fantastic picture of ‘auroral footprints’ in the Jovian system. These are strange bright spots with trailing edges that show up in images of Jupiter’s aurora. They are thought to be caused by electromagnetic reactions with the orbiting Galilean moons!
There are many questions facing us on Earth too. Going back to the sunspot cycle, there are extreme minima that result in prolonged periods of very low solar activity, and these have affected weather patterns on Earth in the past. The ‘Maunder Minimum’ that occurred between 1645 and 1715 resulted in very long cold winters and poor harvests. How often do these minima occur? Are we due one anytime soon? Also, does increased solar activity affect the global climate in other ways- does it contribute to global warming, for example?
Some of the most thought-provoking presentations seem to finish with more questions raised than answers found, and so it was with Ian’s Aurora talk. He inspired us to look forward to the next solar maximum period with great anticipation; maybe we’ll see a dark aurora or hear the crackle of the aurora as it flickers and twists above us in the Highland skies! Here’s hoping; and here’s a big thank you to Ian for his entertaining and warming talk on the Northern Lights.
Eyes on the Skies
It’s June. Pessimists would say there’s nothing to see. That’s not strictly true, but it will certainly be more difficult to make serious observations this month.
It will be hard to actually see true celestial objects through June, as the sky will never really get dark. Only the very brightest stars and the planets Jupiter, Mars, Saturn and Mercury will be at all obvious in the evening sky.
Mars is now very small, but may be of interest on the night of the 16th, as it passes 0.04 degrees away from the Beehive cluster in Cancer. The Beehive has been in many a photo-opportunity in the last few months, as it had Saturn in its environs for quite a while earlier in the year, and the ringed planet is still quite nearby. This little grouping will be very close to the horizon though, so I wouldn’t expect to be able to use very high magnifications to view the planets.
Increasing magnification on other celestial targets is a good way of improving the view in the summer months. You will need to be able to actually find your target, but once acquired, by increasing the magnification you will darken the sky background in the eyepiece and improve the contrast and quality of the view. Of course, the tricky bit is actually finding your target with so few visible pointers around!
Summer can also be the ideal time to bring out the binoculars. Lightweight, easy to carry and use, and giving a huge field of view, binoculars can be great for panning around the summer sky to see just what can be seen when the sky allows. If you are able to detect something of interest in the binoculars, you may be encouraged to set up a small telescope to zoom in for a better view. Or you could just sit back and enjoy the binocular view with a nice cool beer (or warming mug of broth, as the weather dictates).
Remember too to keep an eye (or both) open for the subtle Noctilucent clouds. We are quite favourably placed to spot them, and on fine clear evenings after the Sun has set you may be lucky enough to catch a glimpse of this phenomena low above the horizon, generally in the western or northern part of the sky, as that is where the Sun sets in summer. Noctilucent clouds consist of high altitude ice particles which are illuminated from below by the Sun. The effect is quite striking, and they photograph well, so maybe it will be worth while having your camera handy as well as your binoculars in the next few weeks!
The next meeting will be 2006’s Equipment Night. Members are asked to bring along and display their telescopes, binoculars, imaging equipment, eyepieces, filters, chocolates, star charts and anything else they employ towards the enjoyment of the hobby. You will be able to ask questions of the equipment’s owners and probably get some hints and tips on how to best use your own equipment. These equipment nights are a guaranteed success for beginner and veteran alike.
This will take place at the Green House on Tuesday 4th July, starting at 7.30pm.
Until the next meeting, enjoy Sunny Days and Dark(ish) Skies!