New Home for Green Witch

After eleven and a half years at Dry Drayton we are moving to our new home in Great Gransden. This is only ten miles away by road and is easy to get to from the M11, A14, A428 and A1; we hope to welcome you there in due course.

We've been working hard to prepare for the move which will be complete at the end of this month and we shall open for business in our new home on Thursday 1st July 2010.

Full details of how to find us will be posted on the web site, together with any other changes to contact details that may be necessary. Hopefully, for our internet and mail order customers the change will be virtually seamless and we shall still offer the high level of after-sales service and advice that you have come to expect.

Moving Sale

We're having a long overdue clearout as part of our move and will be selling off some ex-display stuff and other stock that we don't want to take with us. This will include odds and ends we've kept for spares but no longer need.

If you like a bargain then call in to see us soon at Dry Drayton.

The Summer Triangle

We've had several customers recently who have said they don't get their telescope or binoculars out in the Summer as there's not much to see. Actually there is quite a lot see and the warm nights can make observing very pleasant, even if it does mean staying up later for the sky to become dark.

This is the time of year I enjoy browsing the Milky Way as it runs down the left-hand side of the Summer Triangle and into Sagittarius. At present the Summer Triangle is well above the eastern horizon by midnight and it will become more prominent over the next two months.

The Triangle is a useful marker as its three stars are in three constellations and can be used to help find lots of interesting objects. The Ring and Dumbbell nebulae are old favourites, the Coathanger (Brocchi's Cluster) and the double star Albireo are easy to find. Run your favourite planetarium software such as Stellarium (a free download) or Sky Map Pro, turn on deep sky objects and choose a few to look for.

One of the richest areas is in Sagittarius where the intense radio source Sagittarius A* coincides with the position of the super masssive black hole believed to sit at the heart of the Milky Way Galaxy. For UK observers Sagittarius and other rich areas such as Scorpius never rise very high in our skies so if you are planning a summer holiday further south then don't miss the opportunity to enjoy these constellations. Spend a little time getting familiar with what to expect and you will enjoy them all the more.

What is Jupiter Doing?

While Jupiter has been hidden by the glare of the Sun it has undergone quite a dramatic change, losing its southern equatorial belt. This isn't an unprecedented occurance but is nevertheless a puzzling phenomenon.

The different colours seen in Jupiter's atmosphere are caused by different chemicals thought to occur in clouds at different heights. High speed winds in Jupiter's complex weather system cause clouds at different levels to be exposed but we don't know why such a large feature should change so rapidly.

The Jupiter watching season is just beginning again and you can see it in the early hours of the morning before it gets light. As it rises earlier each night you will be able to look for the further changes that will surely come. Jupiter will be at its closest to the Earth on September 24th but can be observed for several months either side of that date. Will you be the first to spot the return of the southern equatorial belt?

Nest Boxes

It is encouraging that we are selling a lot of nest boxes for wild birds. It means that people are concerned to help our feathered friends and that they appreciate the quality of the products we supply. This year in particular the double house martin nests have been especially popular.

The nesting season is well-underway and several fledgling blackbirds have been fed on our lawn by parents looking smaller than their off-spring. So it's unlikely that boxes put up now will be used this year, but not impossible.

However, it is the ideal time to plan for next year. It's so much easier to put up boxes in the fine summer months and it gives them time to naturalise before the birds need them as nests. Good quality boxes will also be used for roosting in the winter, providing birds with the shelter they need to survive bad weather and cold nights.

If you have the ladders out to decorate, clean gutters or carry out other maintenance then why not take the opportunity to put up some nest boxes, especially those that need a high position such as swift boxes.

The Sun is Waking Up Again

After a long sunspot minimum there are signs that the Sun's activity is building again and there have been some lovely prominences on view just recently. Observers have responded to this and we've noticed an increase in sales of solar filters.

Although many text books will tell you how to observe the Sun by using your telescope to project an image onto a sheet of paper we do not favour this method. Besides risking damage to your telescope it is all too easy for someone who doesn't realise what's happening to look through the telescope while your back is turned. And the consequences for their eyesight will be catastrophic.

For white-light observation which shows sunspots, faculae, granulation and limb darkening we recommend making your own filter from Baader AstroSolar Film. This is a very thin but tough and flexible material formulated for solar observation. Using simple 'Blue Peter' technology you can easily and cheaply make your own filter. The instructions for doing so are included with each sheet.

Provided the filter is intact (check for holes against the daytime sky) and secured so that it cannot blow off or be dislodged accidentally then you can safely observe the Sun through it. The filter must cover the telescope objective and any finders should be capped, covered by their own filter or removed.

AstroSolar Film is supplied in A4 sheets and you can find them on our web site.

White-light filters cannot show you flares and prominences. For this you need an H-alpha filter with a very narrow pass band, typically less than one angstrom. Suitable filters are based on the Fabry-Perot Etalon, a device that is very simple in principle but which requires extremely high levels of technology to make it work satisfactorily. Fabry-Perot Etalons are usually used with blocking and order-sorting filters. They are available as sets to be used with conventional telescopes but more often are incorporated into purpose-made solar telescopes.

These solar telescopes can only be used to observe the Sun (nothing else is bright enough) but there is a wealth of rapidly changing activity to make them well-worth while. Most solar telescopes use full-aperture etalons, e.g. a 40mm telescope has a 40mm etalon, and are expensive, typically thousands of pounds. Coronado's Personal Solar Telescope (PST) uses a different approach. It condenses the incoming beam to a small diameter internally so that a small etalon can be used. The result is a an affordable solar scope.

Full-aperture solar scopes give the best views (we recommend Solarview telescopes from Solarscope) but the PST is an excellent alternative.

Has Your Telescope Supplier Disappeared?

We've received many enquiries from customers of a telescope company that recently ceased trading leaving them with no support or after-sales service. We have done our best to help and where possible have sorted out their problems. If you find yourself in this unfortunate position please contact us for help. We can't guaratee to solve all problems but will do what we can.

Stand-alone Autoguider from SkyWatcher

The new SynGuider from SkyWatcher is designed to guide your telescope mount without the need for a PC or laptop. Despite the name it won't take you to a red light district but will simplify your astrophotography. Details are here.

Hats off to Bats

The Wildlife Trust is running Hats off to Bats this summer, a series of events to celebrate and educate about bats in Cambridge. As part of their Cambridge City Greenways Project they are hosting a number of bat walks and bat "punts" along the River Cam, giving you the chance to learn more about these extraordinary creatures.

You can download a poster giving details from our bat section.

And finally...

The Japanese Spacecraft Hayabusa (Peregrine Falcon) is almost back to Earth from its ambitious journey to intercept Comet Itokawa and bring back a surface sample. Many new techniques including ion propulsion and autonomous guiding were built into the mission. Many severe technical problems were encountered and overcome along the way. Despite a successful encounter it is not known whether it collected a sample.

It is due to return to Woomera in mid June when we will find out if its primary objective has been achieved. Whatever the outcome we should congratulate the Japanese for their tremendous achievement.

Clear Skies and Best Wishes

Neil

www.green-witch.com
www.arizonaskyvillage.co.uk