Saturn is Coming Back

Of course Saturn has not been away but for many of us who don't get up early in the morning it hasn't been seen for quite some time. At the turn of the year it will rise around 10:15 at night and by the beginning of March will be more than 30 degrees above the horizon at that time.

While Saturn has been largely hidden from us, the spacecraft Cassini has continued to send back data. Astronomers analysing it have concluded that Saturn's rings may be much older than originally thought, with the implication that they might last much longer. Many people have been uncomfortable with the thought that the rings would only exist for a short period (as far as astronomical timescales are concerned) and that we happen to be here at just the right ime to see them. Now the timescale is thought to be much longer, there is less of a coincidence.

The other recent news from Saturn is that it has an infra-red aurora that behaves differently to predictions, frequently covering the south pole region and changing shape very rapidly. So, new theories on how the solar wind interacts with Saturn's atmosphere and magnetosphere are being developed to explain these unexpected observations.

When Saturn is easy to observe in the evening sky next year the ring system will be close to edge on and will be less than 2 arc-seconds thick compared to around 20 arc-seconds when we see them fully open. So Saturn will not look as impressive as in recent years but will offer an opportunity to look for its smaller inner moons which are often obscured by the glare from the rings.

Why not try to see the eight most visible moons which range from magnitude 8.3 (Titan) to 14.2 (Hyperion). Most of these are within the theoretical range of modest telescopes but your success will depend on conditions at the time and experience. Good hunting.

Astroblast 2008

Despite threatening bad weather and heavy overnight rain, Astroblast attracted a good crowd and proved to be a very successful day. The lectures were excellent and varied, the workshops proved popular and the rocketeers were able to fly their own rockets and to help many children enjoy the thrill of flying rockets themselves.

We were invited to take Astroblast to two other venues next year but having just survived the organisation of this one and with Christmas looming we haven't made any definitive plans. But it looks as though Astroblast is proving very popular.

Christmas is Coming

Now's the tme to make your present list and to start dropping hints. There is always something that the avid astronomer needs but I thought I would make a few suggestions to get you started. You can find these in our online shop along with many other desirable items. There are suggestions for birding enthusiasts and anyone with natural curiosity. Click on the name to go straight to the right section.

• Infinity 76 Telescope. We call it 'Pingu' and it looks like a toy, but it performs really well for astronomy and terrestrial observing. It is light and compact, making it ideal for children, and it won't take up too much house room.
• Skymax 127 Supatrak Telescope. For those wanting a serious first telescope this takes a lot of beating. Suitable for beginners and intermediates it has a good-sized aperture, excellent optics and a simple to set up and use tracking system. We recommend this as one of the best buys in its price range.
• Celestron NexStar 6 SE Telescope. One of the most popular telescopes for all levels of observer. Superior optics with a stylish automated mount that will find and track tens of thousands of objects. Our favourite amongst all the mid-sized telescopes. Lee and his fiancee have one each so you can't get a better recommendation. It has two smaller brothers and one larger one so you can choose the model to suit your budget and aspirations. (The 6-inch model can be fitted with 'Hyperstar' for extra-wide-field astrophotography - the only telescope in its size range with this capability.)
• Eyepiece Sets. Once you have your new telescope you will want to get some extra eyepieces to give different levels of magnification. One of the most cost-effective ways of doing this is to buy a set. We recommend two in particular for beginners. One is called 'Next Steps' and is designed for telescopes with 2-inch focusers, such as the 8-inch Skyliner Dobsonian. The other is the Revelation Photo-Visual Kit which is suitable for almost any astronomical telescope.
• Replica Antique Instruments. We stock a range of well-made working replicas which provide lots of interest for enquiring minds. They also look good and make attractive talking points. If you're not sure what equipment your astronomer already has and what he or she wants next, these make unusual related presents.
• Binoculars. Binoculars are presents that will last a lifetime and bring endless enjoyment. We stock a wide range and are always happy to discuss your requirements and offer advice. Because choosing binoculars is quite a personal thing we will exchange a pair after Christmas if they are given as a surprise present and prove unsuitable for the recipient. (To get full credit for the purchase price they must be unused and complete with all original packaging.)
• Bird Feeders, Food and Accessories. Watching birds in the garden is an inexpensive form of entertainment that anyone can enjoy. What better way to try out your new binoculars? We stock a wide range from CJ Wildbirdfoods which we selected for quality and value-for-money. It also includes nest boxes, badger food, squirrel feeders and some attractive gift packages.
• Working Model Gift Cards. If you want to send someone an inexpensive gift with a difference, these working models in the form of gift cards may be the answer. They are very attractive and really do work.
• The Astronomical Patrick Moore. One of the best autobiographies on DVD we have seen. It truly captures the essential Patrick and is very entertaining. You will enjoy watching it at Christmas and it will become a collector's item in years to come.
• Microscopes. These make unusual but useful presents for students, gardners, hobbyists and many others. We supply a wide range for home, college and laboratory use but the one set to be most popular as a present is the LCD Digital Microscope from Celestron. It has just been given an Innovations 2009 Design and Engineering Award by the American Consumer Electronics Association and makes it easy for anyone to view objects at high magnification without having to peer into an eyepiece.
  

We get lots of phone calls that start with 'I want to get something for my wife/husband/partner/friend who is interested in astronomy/bird-watching/scientific instruments but don't know what would be suitable. Can you help?' Often we can, so don't hesitate to call if you want advice.

Relationship between UTC and GPS Time

A customer came in on Saturday with a question about his Meade telescope that wasn't finding objects as it ought. He bought the telescope elsewhere but couldn't get much help from the retailer so has been coming to us with a series of problems that we've helped sort out. Whilst investigating his latest problem he had come across the 'GPS-UTC offset' parameter and wondered what it was. It was set to +13; was this correct?

The answer lies in the way we measure and use time. Until 1956 the second was defined as a fraction of the Earth's mean period of rotation, but demands for increasing accuracy meant the Earth's rotation was no longer consistent enough. The second was then redefined as a fraction of the time it took for the Earth to orbit the Sun. In 1967 further demands for accuracy brought about the use of Caesium atomic clocks, which form the basis of present-day time measurement. We call this time scale UTC and it is the basis for the civil time we use every day.

When measured against UTC the Earth is slowing down and its days are getting longer. The rate of slowdown is imperceptible to us but is sufficient to require an adjustment to UTC to keep it in step with the Earth, and every so often a leap-second is added.

When GPS was established in 1980 it was synchronised with UTC. But leap-seconds are not added to GPS time so it is now different from UTC, hence the offset in the Meade handset. Leap-seconds are added in June and December; some years two are added, some years one or none. Since 1980 there have been 14 leap-seconds so presumably this should be the setting for the GPS-UTC offset.

A quick search on internet forums brings up conflicting advice with some people saying that changing this setting to zero has cured their pointing problems. GPS signals do carry information about the leap-second offset but Meade do not say if or how they use it. So, if your Meade telescope is not pointing as well as expected you could try setting this parameter to zero. If it makes things worse you can always set it back to the current offset of +14 seconds.

New Maksutov-Newtonian Telescope from SkyWatcher

Maksutov-Newtonian telescopes have a reputation for producing exceptionally fine images that are comparable to a high-performance refractor but at a fraction of the price. SkyWatcher have now introduced their 190MN which is ideal for astrophotography and visual use. We've taken delivery of our first batch and have one on display in our showroom for those of you who are able to visit us. Our initial tests confirm that its performance is superb and it is very well made. Details are here on our web site.

New Telescope from Meade?

It has not been announced officially but rumours abound about a new telescope from Meade. It's called the ETX-LS and isn't due to be unveiled until next year but a web search will give you details. Is this Meade flying a kite to see what the reaction will be? Or is it a genuine leak? Only time will tell.

Celestron Bargains

If you want a real bargain why not try the Celestron C6 -S XLT? It has the same optics as the NexStar 6 SE but is on a CG5 German Equatorial Mount. The model has been discontinued and remaining stocks are being sold off at 349 pounds (original price was 649 pounds, recently they were 509 pounds). There aren't many left so please contact us soon if you want one.

Looking South at 10 pm from Cambridge UK

Our southern meridian starts at Andromeda's feet close to the overhead, and runs down through Trangulum, the boundary between Aries and Pisces, Cetus and Fornax. To the right the Geat Square  of Pegasus is easy to pick out and makes a good starting point to find the Andromeda Galaxy which is about twelve degrees to the right of the meridian. To find it I start at the top left star in the square of Pegasus and move two bright stars to the left, a distance similar to one side of the square. This star (Beta Andromedae) marks the foot of a Y-shape made of two stars for the upright and two fainter ones for the tips of the Y. The galaxy sits right on top of this Y. If you can't see it with your naked eye try binoculars.

The small constellation of Triangulum is easy to recognise; the narrow triangle being marked by three stars. The lower right one is Alpha Trangulum and if you search the area between here and Beta Andromedae (the foot of the Y described above) with binoculars you should be able to see M33, the Pinwheel Galaxy. It is another member of the local group along with Andromeda, but is smaller, fainter and a little further away.

Continuing down from Triangulum we pass just within the western boudary of Aries the Ram. This was the flying ram that tried to carry the King of Thebes' two children, Helle and Phryxus, to safety. As in all good stories the wicked step-mother was out to get them. Unfortunately, Helle fell to her death in the stretch of water now known as the Hellespont, while Phryxus survived. When the ram died its golden fleece was hung in a sacred grove until Jason and the Argonauts removed it. Aries is also recognised by its three brightest stars that lie in a line below Triangulum.

Travelling further south we pass through the corner of Pisces and into Cetus. This large but unremarkable constellation is usually referred to as the Whale but has been thought to be the sea monster in the story of Perseus and Andromeda. One of its most famous stars is Omicron Cetae, better know as Mira, which gives its name to a whole class of pulsating red giant stars. Mira is not usually visible to the naked eye but for a few weeks each year flares to around magnitude 2 and is easily visible if its flare occurs when we can see it.. Cetus also contains M77, the most massive galaxy in the Virgo Cluster. It is a Seyfert galaxy, is believed to contain a central black hole, and is a strong radio source. Our meridian runs through Cetus' body; Mira, M77 and Cetus' head lie to the left.

Right on the horizon and lying mostly to the left of our meridian is the faint constellation of Fornax, the Furnace. Formerly called Fornax Chemica, the Chemical Furnace, it goes largely unnoticed from the UK but contains a large cluster of faint galaxies.

And Finally...

Congratulations to India on the success of its Lunar spacecraft which is sending back high-resolution images of the surface and has crashed a probe into it. This is quite an achievement and shows lots of progress from the days when the Indians wheeled their rocket parts around on bicycles. They still manage to do things much cheaper than anyone else.

Clear Skies and Best Wishes

Neil

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