Stargazey Pie May 2006
(This time by Trina Shaddick- with thanks from Antony)
Welcome again to the Highlands Astronomical Society’s monthly newsletter. Our usual deft newsletter writer Antony McEwan was unable to come to Tuesday’s meeting and I’ve been happily volunteered to do May’s Pie in his stead (although I can’t take the credit for “Eyes on the Skies”). I must admit that it takes me thrice the time to write up as it takes Antony, hence the slightly later release of Pie following the meeting. Hope it’s worth the wait.
With spring merging into summer and any opportunity to enjoy the night sky narrowed down to the wee small hours, the Highlands Astronomical Society met once again on May 2nd at the Green House, in Inverness. As you may know, Alyson Calder was unable to come and present her talk advertised for this date on our Programme. Hopefully she will be able to come and speak to us another time. Instead, Tuesday’s meeting was a members evening and our very diverse, provocative and entertaining speakers were: Donald Boyd with his thoughts on the cosmos from a Christian perspective, Arthur Milnes in his element with a Geiger Counter, and Rhona Fraser sharing her experience of the total solar eclipse of March 29th this year, which she watched from the Sahara Desert.
In the absence of our Chairwoman, Pauline Macrae, Maarten de Vries opened the meeting with the following notices:
- Sat 20th May. The Scottish Astronomers Group (SAG) meeting will be held at the Calton Hall Observatory courtesy of the Edinburgh Astronomical Society. Doors open at 12 noon for some solar observing (weather permitting), meeting starts at 1.30 pm. If you are able to go you are asked to bring something to share; pictures, observations, sketches, and anything else you have.
- BBQ. Sat. 10th June Simon Urry is having a barbecue from 3.30 pm onwards at his house near Fortrose. If you would like to come, please contact our secretary Pat Williams whose contact details are given below.
- SAG. president Bill Ward has been in touch with the Manager of the visitor centre at the Royal Observatory Edinburgh, who emailed to ask about involving astronomical societies in events planned by ROE for 2007. These events are planned in conjunction with the Forestry Commission with a view to making use of forested areas (potential dark sky sites). We are asked to let Bill know if our society is interested in participating. Events planned by ROE also include an Astrodome, and also further use of the Faulkes Telescope North in Hawaii. This 2m computer controlled telescope can be used via internet from anywhere in the world, and used to great effect at last year’s Going Nova event in Forres.
- Going Nova 2. Following the success of last year’s three day event, Going Nova is planned again at Horizon Scotland later this year. Although dates are not yet fully established, this is proposed to run from Wednesday 22nd to Saturday 25th November. Events will take place during the daytime, and also in the evenings, and will include various talks and activities at venues in Forres and Findhorn. If you would like to help with the smooth running any of these events, please contact the committee.
- Raffles. Do you like the idea of a raffle every HAS meeting? As we now have charitable status we are in a strong position to raise public funds towards our planned new observatory. However, we still need ideas on how to raise funds ourselves at a more grass roots level. Members were asked at the meeting whether we liked the idea of a monthly raffle, and a healthy show of hands were held up in support. (Let’s face it, the chance of winning something increases significantly!)
- Double Trouble. Our observatory committee has doubled in size over the last month or so. Members now include; Rob Nuttall, Bill Jappy, Arthur Milnes, Antony McEwan, Pauline Macrae and Maarten de Vries.
- Moving Soon. HAS awaits a phone call form the NTS, probably sometime in June, asking us to move the JSL Observatory from its site at Culloden Battlefield in time for work to begin on the new visitor centre. Any help will be greatly appreciated.
- Watch Out. The Aurora Watch website may soon sadly cease to exist. If you are a subscriber you will have received an email from J. Wild informing you that the government funded body PPARC are planning to stop funding this service. Please reply to him if you wish it to continue. The address is firstname.lastname@example.org
- Programmes. Pat is printing out more programmes. If you don’t already have one, you can expect one in the next few days.
- Subscriptions. Members are reminded that all subscription fees are now due
Eyes on the Skies
If you’ve been reading the astronomical press, visiting astronomy websites, looking at online galleries, or even been anywhere in this solar system for the last few weeks, you should have at least heard of Comet 73P/Schwassmann-Wachmann 3. This comet actually fragmented last time it came by in 1995, and it now consists of a couple of dozen or so fragments! These are subtitled with letters of the alphabet, and the brightest and easiest to locate are named C, B, G and R. They are passing rapidly through the rising summer constellations of Corona Borealis, Hercules, Lyra and Cygnus. The comet is getting a lot of attention from amateur astronomers around the world, and it is being heavily observed and imaged. Many observers are suggesting that the comet is still breaking up, and that segments are breaking off the already numerous fragments.
The various portions of the comet are passing through a relatively easy part of the sky to observe, and are passing close by easy to find celestial landmarks, as can be seen by the various finder charts on the internet. Note that the Heavens Above website update their finder charts daily. But this is where it gets interesting… Some people can find the comet bits easily, and others (myself included) are spending hours at the eyepiece and finding only tiny pinpoints at the designated locations. Certainly portion C should be brightening to about magnitude 3.5 over the coming weeks, so should be easy to spot- but I’ve yet to see anything in the eyepiece that appears comet-like. I’d be interested to hear of any successful observations made by Society members, including details of what telescope apertures and magnifications were used. Perhaps these reports could be posted on the message board? I also will keep on hunting, of course, as I like comets. Trouble is, my first comet was Hale-Bopp, and that’s a bit of a hard act to follow.
Jupiter is now rising at sensible times, though will stay low over the southern horizon. In contrast to the elusive cometary fragments (mutter, mutter…) the gas giant should be nice and easy to find, as it will be the brightest thing in the sky apart from the Moon. By the time you read this, there should be a Jupiter Observing Guide on the Spacegazer website, so why not spend some warm clear evenings soaking up the Jupiter rays with your small (or large) telescope? If you see anything interesting, you could always let us know on the website.
Of course it doesn’t get dark until quite late on now, and even then it doesn’t stay dark very long. Deep sky objects are still around though, and Leo is really quite high in the south-western sky when it gets dark, so if you can stand the late nights it could be a good time to hunt down a bundle of galaxies in the few remaining hours of proper darkness before summer comes along.
The Main Events.
Donald Boyd talked first on the subject of a Christian perspective on the cosmos, taking a more theological angle than most of our talks. He touched on the questions that any curious person who has ever looked up at the night sky has asked. Who are we, why are we here, how did we get here and how did it all begin? He talked about alternative notions including a new idea to most of us; that of White Holes.
Today, cosmologists think that the origins of the universe can be traced back to the first few seconds after the big bang. To make sense of the big bang theory which assumes a beginning of the universe, very special conditions would have had to exist in the first few moments after the event. So exactly what went bang? That’s the question Donald asked opening a cosmic can of worms in the process. White holes suggest an alternative to the most popular theory of universal origin where time, space and everything grew out from a singularity?
What are white holes? They seem to be a very hypothetical opposite of black holes. Everything that goes beyond its event horizon gets pulled into a black hole. A white hole would be the “other side”, out of which everything is blown (I think). Why do they appeal to Christians? Perhaps because you don’t need to pull apart the fabric of the universe to find its origin; somewhere along the line they allow for creation out of nothing.
The anthropic cosmological principle offers a theological angle. In a universe in which the chances of life on earth are tremendously improbable, the fact that we are here to see it at all supports belief in a creator with intent. Just suppose then, God created the universe. Why would he do that; perhaps to make sure that we are in no doubt about just how small we are?
We can argue about it but there’s no doubt that whatever your thoughts about cosmic origins, you have to agree, the universe is a deeply intriguing place where science and theology come face to face.
Next up was Arthur Milnes with a Geiger counter. Over the years the poor thing had been misused (but enough about Arthur). Fortunately, it was rescued by Maarten, and now has a new home in Arthur’s workshop. Having a soft spot for instruments of this special scientific nature, Arthur has given it an overhaul and a brand new lease of life and it appeared at Tuesday night’s meeting happily clicking away.
It was an elegantly crafted and curious apparatus that would have looked quite at home in an old lab. It comprised a Geiger-Muller tube containing an electrode and some halogen; this connects up to a battery and counting equipment. Arthur explained how it worked and I did my best to listen.
It is based on the ionising effect of radiation. When an alpha or beta particle passes another atom it pulls electrons off it. As a radioactive particle enters the tube it strips an electron from a halogen atom. This in turn travels toward the charged wire setting off an “avalanche” of electrons. These electrons rush toward the wire, creating a pulse which is what is amplified and counted by the instrument. That’s as much as I can say. If you really want to know how it works, best ask Arthur.
Switched on, it clicked away every so often due to cosmic background radiation. Arthur then demonstrated using a gas mantle filled with thorium isotope and a few more clicks were given out. 232Th has a very long half-life, as long as the estimated age of the universe, and we apparently eat 3 micrograms a day. Then he produced a small object wrapped up in aluminium; a watch with a radium dial. Radium has a half life of 1600 years, and the clicks were much more frequent. One atom of radium decays each second inside us.
Arthur talked a little about some different aspects of radiation. Henri Becquerel’s discovery in 1896 of how uranium darkened a photographic plate sealed away from light. The Curies went to great lengths to discover radium, an element that had a deadly effect upon unsuspecting workers in the factory as they painted radium soaked substance onto watch dials. They would lick their brushes to get a point. They were simply unaware of the danger.
After the break it was Rhona’s turn to tell us about her Mediterranean cruise, the highlight of which was a total solar eclipse. Unlike the 1999 eclipse which comparatively few people in the UK saw because of cloud cover, this one was virtually guaranteed to be seen, as long as you went somewhere within a band which stretched across North Africa, as did around a million tourists. And many gathered together at a little known spot called Jalou in the Sahara Desert.
Rhona’s cruise ship docked the Libyan port of Benghazi. Rhona had to get up at 2am to leave the ship and journey on one of 20 buses which convoyed, with a police escort, for 500 km through the Sahara there and back. The temperature outside was around 28°C and as if to tempt fate, the livery on the buses read “El Joker Travel”. Rhona’s coach (no.13 if you please) broke down on the way, adding hours to the long 7and a half hour journey. All this for a four minute eclipse!
Despite having 2 cameras and tripods, technical gremlins ensured that none of Rhona’s pictures came out. Still, she had some spectacular pictures to show us. She described an eerie event. As the temperature fell, causing a change in pressure, wind blew up just before the eclipse sending sand and dust swirling. The photos also showed the peculiar light so unique to an eclipse. She described a phenomenon called shadow bands – moving bands seen on the sand perhaps caused by refraction in the atmosphere. Other photographs showed the phases of the eclipse including the fantastic diamond ring effect. Solar prominences were visible around the Sun’s limbs, and the Moon’s cratered edges let through tiny chinks of light called “Bailey’s beads”. Then, at totality, a stunning corona appeared with field lines or streamers radiating out.
Rhona had cruised to Crete, visited Athens, and spent some time on the volcanic island of Santarini. Then she spent some time in Benghazi attending lectures with other eclipse tourists. A day trip to Ceyrenne to visit ancient ruined temples provided a dry run for the big journey, then she topped it all off with a total eclipse of the Sun.
What an adventure!
Next Time. (Change to published programme)
Our guest speaker for June 6th is Ian Brantingham from Sigma talking about the Aurora. Keith Horne will now speak about gravitational lensing on the 5th of December. Keith sends his apologies to the society for the change of date, and thank you very much Ian for stepping in at short notice. The meeting will start at 7.30 sharp and will take place at the Green House. Between now and then enjoy all the dark skies you can find and be sure to visit the spacegazer website and leave a note on the message board if you see anything interesting, wierd or wonderful.