Happy Birthday William Herschel...

...not the man but the telescope. I've just read Chris Kitchen's article in Astronomy Now celebrating the 20th anniversary of first light on the William Herschel Telescope (WHT) on La Palma. It came as a bit of a shock as it doesn't seem long since I took over the WHT from Brian Mack who had supervised its installation culminating in first light. My job was to complete the commissioning of the telescopes and instrumentation then bring it into regular, scheduled use alongside the Isaac Newton and Jacobus Kapteyn Telescopes.

There is always a tension when a new telescope is being commissioned. The engineers want to 'finish it off properly' while the astronomers can't wait to get their hands on it, even if the fine tuning is not complete. To deal with this we operated for the first year in a 'shared risks' mode where university astronomers were given large chunks (three weeks) of time for programmes that could make good use of this unique opportunity to get so much time on a large telescope, but, on the understanding that the engineers could take over if and when problems showed up. Fixing the problems, and not just working around them, would then get first priority.

As it happened, the WHT was in such good shape the astronomers got almost all the time they were allocated and some excellent science resulted. The WHT probably came on line faster and more effectvely than any previous large telescope.

The first scientific paper to be published during this period was entitled "The William Herschel Telescope is Excellent". It is good to see from Chris Kitchen's article that it has gone from strength to strength and continues to be a world-leader, despite the eight- and ten-metre telescopes that have since been built.

At the time of building it was Europe's largest telescope and the third largest in the world. It was the first large telescope to use an alt-azimuth mount successfully and had one of the best instrument suites available. Let's hope it continues to thrive for the next twenty years and beyond.

Beginners Courses in Astronomy - 30th June 2007

Why not spend a day or half a day getting a good introduction to astronomy. We are running two short courses which are designed to be fun and informative, and are aimed at beginners. In the morning Lee covers the practical aspects of getting started in astronomy and shows how to use a telescope and other equipment. In the afternoon Lee will conduct a guided tour of the Universe travelling from the Earth into deepest space.

You can book a place on either the morning or afternoon course, or on both. Full details are on our web site but please phone us on 01954 211288 if you have any questions.

Venus and the Beehive

If you've had any clear skies at all recently you can't have failed to notice Venus shining like a beacon in the western sky as it gets dark. Over the next few nights it will pass very close to M44, the Beehive Cluster, so you may like to take the opportunity to see if you can see it. You will need to wait until the sky is dark enough and will need binoculars or a small telescope. Venus passes just above it and comes within a degree of the cluster's centre. The cluster itself is about a degree across.

Throughout the month of June Venus will approach Saturn, coming within a degree of it on the 30th. On the night of June 18th the crescent Moon will be between Venus and Saturn which are then about eight degrees apart. This should make a good picture, especially if you plan in advance to take it with an interesting skyline in the foreground. Why not have a go and submit your picture to Astronomy Now's Hotshot Competition?

Thomas Harriot 'the greatest scientist you've never heard of'

Jeffrey Barham introduced me to Thomas Harriot who lived between 1560 and 1621. Despite being an exceptional mathematician and astronomer, he does not figure highly in the public perception, mainly because he didn't publish his work at the time and its influence was thus quite limited. However, his documents came to light some 150 years after his death and revealed that he had made several discoveries before the people to whom they are usually credited. One example is Snell's law of refraction, and he appears to have made better and earlier maps of the Moon than Galileo.

His lack of publications is variously ascribed to a retiring personality and to the political climate of the time. A protegee of Sir Walter Raleigh, he was arrested on suspicion of being an aethiest and of being involved in plots against James 1st. Raleigh was eventually executed and it may have been that Harriot decided that keeping his head down was better than losing it.

The description of Harriot in my title is taken from a web article in National Geographic Magazine; he is of interest in the USA because he wrote one of the earliest descriptions of Virginia and its natives while on expeditions run by Raleigh in an attempt to settle in North America.

He was ahead of his time in other ways too, sadly dying of cancer that was probably related to his heavy use of tobacco which he advocated as an aid to good health.

Summer Barbeque and Creatures of the Twilight - Saturday 7th July 2007

We've been invited to take along some telescopes to this event being run by The Huntingdon Area Group of the Wildlife Trusts at Grafham Water. It features a walk around Grafham at night to look for bats, owls, moths and any other creatures that come out at night, including astronomers. If the weather is clear we shall be showing people some of the delights of the Summer sky as well as enjoying the other attractions and barbeque ourselves.

If you would like to join us you can obtain tickets by calling George Cottam on 01480 450809 or Jo Thomas on 01480 370593. The price is £7 for adults and £4 for under 14s, and covers food as well. The date is easy to remember, 7/7/07, and it starts at 8 pm at the Mander Car Park, west of Perry Village. Please obtain or book your ticket in advance to help the caterers.

Looking South at 11 p.m.

In the last newsletter I introduced the idea of describing what is due south at 10 p.m. as a way of helping beginners learn the night sky. This week I've moved the time to 11 p.m. to allow it to get dark but the idea is the same.

At 11 p.m. the kite-shaped Bootes with its bright star Arcturus will be just to the right of the meridien but can be used as a starting point to find tonight's objects. To the left of Bootes lies the small but attractive constellation of Corona Borealis, the northern crown. It is usually depicted as a tiara rather than a crown and is supposed to have been given to Ariadne by Bacchus the wine god.

The crown is usually depicted with seven stars that form the tiara shape. Close to the second one from the left lies T Coronae Borealis, sometimes called the blaze star because it has twice been observed to flare from its normal magnitude of 10 to become visible to the naked eye at second or third magnitude. Previous flares occurred in 1866 and 1946. A linear extrapolation would suggest it's due in 2026 but it could happen any time so keep your eye on it.

Lower down the sky and almost on the meridien you can find Serpens, the head of the snake that Ophiuchus is wrestling. A small, easily recognised triangle marks the head with a portion of the snake's body hanging beow it. To the right you can find the globular cluster M5, second only to M13 in Hercules. It's on the limit of naked-eye visibility but looks very impressive in a telescope.

Nestling close to the horizon below Serpens is the zodiacal constellation of Libra, the scales. You may be able to imagine the outline of a set of scales lying on their side.

Amateur Spectroscopy

Spectroscopy is the most important technique used by professional optical astronomers and is fundamental to research in astrophysics, but, it is largely ignored by amateur astronomers. Now a book edited by Stephen Tomkin called Practical Amateur Spectroscopy shows just how much an amateur can achieve, from recording the spectra of different types of bright stars to measuring radial velocities.

If you are interested in taking your astronomy further or just want to learn about the techniques involved then this book, which is written by people doing spectroscopy, is a good place to start. We now have it in stock; please call to order yours.

And finally...

One of the three-week observing periods on the William Herschel Telescope I mentioned above was devoted to observing the bright star Arcturus. It was the idea of George Isaacs from the University of Birmingham who attempted to discover the first extra-solar planet. Unfortunately he didn't succeed but he did show that if there was a planet orbiting Arcturus it must be smaller than a certain size.

It is interesting to note that all the extra-solar planets we now know about have been discovered since the WHT saw first light only twenty years ago.

Best wishes and Clear Skies

Neil
www.green-witch.com
www.arizonaskyvillage.co.uk
www.astroblast.org.uk