Stargazey Pie, November 2004
Antony McEwan's monthly digest of HAS happenings.
November. As well as being a time of increasing cold and longer nights, it’s a time when we realise that the year is slowly drawing to an end… The perfect month for a talk on the measurement of mankind’s most loyal companion: time itself! With an astronomical slant, of course. The meeting was particularly well attended with only a few seats left empty. A suitably large audience then for a particularly impressive array of announcements, delivered as always by chairwoman Pauline:
• Colin Donaldson - Spaceman Congratulations go to Colin Donaldson, one of our junior members and a member of our Committee, who has been accepted for Space School! He was given numerous astronomically related essays to write and questions to answer over the summer. Some youngsters would do well enough to go to the Space School in Scotland, but the very best go to Texas - and Colin is one of those. Apparently the standard was very high this year. Fantastic news, so well done and good luck Colin.
• HAS-Wear A second sample sweatshirt has been received from Dallas Embroidery, the company in Elgin which has been selected to supply HAS branded clothing. The second sample is much better than the first one, with a circular logo and the lettering done in a much more legible font. Catalogues are available for your perusal, but the order for this batch is being placed on Tuesday, so if you require something urgently please contact Pauline before then. Tempus fugit… Orders can also be taken at the next meeting, but they will not be ready for delivery until the January meeting - too late for Christmas prezzies. Also available are HAS-branded mugs, which can have your name printed on them, at £4.50 each.
• HAS-Pens Also available next month will be super-handy red-light pens with the Highlands Astronomical Society logo printed on the side. These combine a fully functioning red light torch and a real working pen. The light shines over the point of the pen so you can record your observations in the dark without losing your night vision. Could also be useful for recording your dreams when you wake up in the night… Battery and “inside bit” (that’s Chairperson-speak) are replaceable too. The price will be £2.00 each. Thanks to Alan Mumford for organising these handy accessories.
• Calling all youngsters… Ray Owens will be giving a talk especially for children at next months' meeting. The subject will be the Solar System, and it should be very similar to the talk he gave this time last year, which automatically means that it will be a lot of fun and informative too. Although Ray has given many talks to schools in the area and is considered to be a trusted individual (and great speaker) Committee member Arthur Milnes will sit in on the proceedings. The children will be provided with lemonade and squash, little cakes, crisps and grapes. There will also be a children’s raffle with tickets selling for 20p. If you wish to bring a child please contact Pauline to make arrangements.
• Observing Nights The dates of this November’s observing sessions at the Culloden observatory have been announced. They start at 8pm and will finish at 11pm (allegedly) assuming that the nights are actually clear. Dates and contacts are as follows:
Friday 12th November……..Maarten
Saturday 13th November…..Rob
Friday 19th November…….Pauline
Saturday 20th November….Trina
• January Meeting Advance warning was given that the date for the January 2005 meeting will be 7.30pm on Tuesday 11th, not Tuesday 4th as advertised. We are advised that this is because the Green House (and possibly the Committee) will still be recovering from the New Year…
• Solarscopes Society member Arthur Fraser brought along his new solar projection telescope, called the Solarscope. This is a small flat-packed projection device that allows for very safe viewing of the Sun. The image is projected into the back of the cardboard mounting so that it is viewed against a dark background, which should give it good clarity and sharpness. Arthur bought his Solarscope in a new shop called Mind-Stein in the Victorian market arcade in Inverness. Thanks to him for bringing it along and showing it off. Now all he needs is some Sun…
Eyes On The Skies The November skies are full of wonderful objects to view. On the planetary front, Saturn is rising in the East just after 9pm, and is a beautiful object in any size of telescope. Give it time to rise high in the sky if you want to get the best out if it though, as viewing through the lower unsteady air and thicker layer of atmosphere will block all but the most obvious detail. 11pm to dawn are much better times if you want to see subtle shaded rings or storms on the planet's globe, or the Cassini division which divides the bright A and B ring systems.
Pauline’s constellation of the month was actually a trio of constellations comprising Pisces, Aries and Triangulum. All of these are fairly high in the sky all through the month and worthy of exploring in the dark period prior to the New Moon. Triangulum is home to the magnificent face-on spiral galaxy M33. This has very low surface brightness and is best caught using a wide field and low power, or even binoculars. It’s virtually impossible if there is any moonlight about, but if you’re lucky enough to spot it you’ll be glad you made the effort. It covers an area four times the size of the full Moon. More information about these constellations is in the Society’s article in the Friday, 5th November edition of the Inverness Courier.
The constellation of Orion is also climbing to observable heights in the late night and offers many interesting things to see for telescopes of all sizes, and binoculars too, including double and multiple star systems (Alnitak, Theta2 Orionis, Lambda Orionis and many others), and some great nebulae, particularly the Flame Nebula, Great Orion Nebula and the subtle Barnards Loop, which encompasses nearly the entire height of Orion to the left of the familiar asterism.
The Main Event The meeting's main talk was 'Sundials' given by Dr David Gavine, who has a comprehensive background in science and astronomy. Born in Dundee, he has a BSC in Geology from St. Andrews, MA in Geography from Aberdeen and a PhD in the History of Astronomy from the Open University, and has been a past president of the Astronomical Society of Edinburgh and the Scottish Astronomers Group. At one time Dr Gavine was Master at Fort Augustus Abbey School, where he made a small planetarium and set up a reflecting telescope on the Abbey roof, the mirror from that telescope is now housed in our own society Dobsonian. He is currently retired, but organises the SAG weekends and still finds time to visit astronomical societies and give lectures.
Dr Gavine started off by telling us that sundials are extremely common and that there are many books about them, as well as a British Sundial Society. For those with a particular interest, he recommended 'Sundials' by Chris Daniel.
A sundial uses a marker or 'gnomon' which points directly to the pole star and casts a shadow as the Sun moves around the sky. The time is found by reading off where the shadow falls on a set of markings around the gnomon. Now, that sounds simple enough, but, as we learned, it’s actually incredibly complicated and something of a lost art. Apparently 'dialling' was taught in many Scottish schools two to three hundred years ago, as well as Astronomy and Mathematics, so that having learned the processes involved, any student would be able to construct their own sundial which would be functional and accurate. These were used for a long time before clocks became the time-keeping standard, and sundials were actually used to regulate the first clocks.
The length of the day varies through the seasons because of the elliptical orbit of the Earth around the Sun, and the tilt of the Earth's axis to the ecliptic. Therefore, a formula had to be developed that would allow sundials to give accurate local readings, no matter what the time of year. Thus was born the Equation Of Time. Sounds impressive, and it is, enabling sundials to be accurate to within just a few minutes.
Unfortunately, sundial accuracy these days is not as common as it once was, as a lot of them are simply erected in gardens as ornaments with no thought given to setting them up correctly. Many, however, are fully operational and accurate, and are maintained to a high standard. We saw many slides of sundials which were beautifully maintained and operational, including ones at Chichester Cathedral, St Margaret’s Church near Westminster Abbey, and even at Elgin. As well as standard sundials, many sundial constructors designed very ornate and intricate ones as a way of showing off their talent. Some have many faces, each of which bears a sundial, and others are actually able to tell the time in different parts of the world.
The talk was really fascinating and was peppered with facts about the history of time-keeping and how different societies thought about time. For example, it was the Saxons who divided the night into 'watches' and the day into 'tides'. The early church developed their own system of Canonical Hours to regulate their religious duties and assign different services to each part of the day or night. Such was the enjoyment of the talk and excellent slides that I think we all hope that not too much time passes before we can welcome Dr Gavine back.
Spot the Sundial! Inspired by Dr Gavine’s talk, a challenge has been issued by the society: Find a sundial in Inverness. Not in a garden centre or car boot sale, but an actual working sundial attached to a building or garden, somewhere in Inverness. If you can find one please let us know at the next meeting or beforehand and you could be eligible for a star prize. (Mini Mars bar anyone…?)