It's around this time of year that we all think about dusting off our telescopes and getting ready for the new observing season.  To help you with this we are offering a check-up and collimation service for your telescope. For a fee of £25 we will collimate and check out your telescope and carry out any minor adjustments. This includes cleaning up to two eyepieces. You will need to leave your telescope with us for a few days depending on how busy we get.

 If we find any major faults or that the telescope optics need cleaning we will contact you to discuss the cost of repair, and whether you wish us to carry it out, before taking any action. We expect this service to be quite popular so recommend bringing your telescope along before the rush starts.

As a further way of encouraging you to get ready for the winter observing season we have a range of special offers that will save you money. These are valid while stocks last and include:

• SXV-M25 CCD camera from Starlight Xpress (save £395 - £495 when purchased with a William Optics refractor)
• Orion Optics OMC 200 - an 8-inch Maksutov-Cassegrain OTA with stunning performance (save £250)
• Lots of smaller items, both new and ex-demo

Please keep an eye on our web site for other bargains or call in to browse.

The four Space Files DVDs are one of the best ways of learning about the Universe. They are ideal for anyone wanting a comprehensive introduction to all we know about the Sun, planets and deep space.

To enter the competition all you have to do is email Wendy with your estimate of the number of unique products in our online catalogue. (We don't expect anyone to have the time to count them but there's nothing to stop you if you really want to…).

We are holding a special one-day event with even more equipment on display than usual plus mini-workshops to explain how to choose telescopes, microscopes and accessories. If you are thinking about buying someone a microscope or telescope for Christmas this is an ideal time to find out what's available.

Our Autumn Season of courses starts soon and you can find full details on our web site. The Beginners Course is now being run as two half-day courses, one on the practical aspects of observing such as setting up and using a telescope, while the other covers the 'armchair side' of astronomy with an introduction to the solar system and deep space. Both aspects will be covered on the same day so you can book either or both depending on your requirements.

M13 is the best globular cluster to observe from the British Isles and is just visible to the naked eye on a good night. Approximately 25,000 light years away and containing an estimated one million stars it appears as a faint, fuzzy ball whose centre is brighter than its edges. A six-inch telescope will resolve many of the stars around the edges. Large telescopes have resolved about 30,000 stars but they are too close together in the centre for individuals to be picked out. Even in the centre they are thought to be about a tenth of a light-year apart so collisions are probably rare and the cluster may have existed for 10 billion years, more than twice the age of the solar system.

The stars appear to contain mainly hydrogen and helium and little of the iron, silicon or carbon that we find in our own Sun. This leads astronomers to suppose that they must have formed from gas uncontaminated by the debris from supernovae explosions and therefore must have formed before any supernovae had gone off. This would make them the oldest stars in the galaxy.

If the idea of finding and looking at the oldest stars in the galaxy appeals to you then follow these instructions taken straight from 'Turn Left at Orion' to find M13.
" Find Vega, a brilliant blue star, the westernmost of the stars in the Summer Triangle; and Arcturus, the brilliant orange star that the handle of the Big Dipper (or Plough) points to. Draw a line between these two stars and split it into thirds. A third of the way from Arcturus to Vega is a half circle of faint stars called Corona Borealis (the Northern Crown) in which the bright star Gemma (also called Alpecca) is set.

Two thirds down the line from Arcturus (or half the distance from Gemma to Vega), high overhead on a Summer evening, are four stars that make a somewhat lopsided rectangle called the Keystone. Find the two stars on the western side of this box, the side towards Gemma and Arcturus. Go to the point half way between them and aim a bit north.

A classic test for a good clear night is to try to see M13 with the naked eye."

Turn Left at Orion contains diagrams to help use these instructions to find M13. It does the same for over a hundred interesting objects that are suitable for a beginner with a small telescope. The information about globular clusters I've given above was also extracted from Turn Left at Orion and I thoroughly recommend it for anyone who has seen the Moon and Planets and wants some help to expand their horizon and explore deep space.

As a complement to Turn Left at Orion I also recommend A Walk Through the Heavens which you can use without a telescope to learn your way around the sky. Starting with the Plough it shows you how to find all the major constellations and asterisms in the northern skies. These 'landmarks' will then help when using Turn Left at Orion. We sell more of these two books than any others on astronomy.

'The bigger the aperture the better' is often heard in telescope discussions and arises from the need to collect lots of light to make faint, distant objects visible. Large apertures also have the potential to reveal more detail since resolution is directly proportional to aperture diameter, all other factors being equal.

But these other factors can mean that you get a more pleasing view through a smaller telescope than a big one. Optical quality and optical design are important factors, and the atmosphere has a more pronounced affect on image quality as the aperture increases.

Add to these the inconvenience of handling a large telescope and it is no wonder that many people are discovering the delights of a simple light-weight setup based on a 70mm or 80mm refractor. Modern electronic detectors also make it feasible to take stunning deep-sky images through these small telescopes.

William Optics make some of the best small refractors and have gone to great lengths to make them feel and look good as well as deliver high performance. If you haven't tried one yet why not call at Green Witch to see them for yourself. They are great for terrestrial use as well and can be fitted with image erectors or star diagonals as required.

William Optics also make larger versions and we can supply any telescopes or accessories in their range.

If you attended this year's Astroblast in Cambridge we would like to hear what you thought of it and whether it should be repeated next year. All the feedback we've had so far has been very positive but if we do it again we want to make it even better and welcome your suggestions.

Best wishes and Clear Skies

Neil