On Saturday 4th April, 2009 I attended my third and final night of Spring Moonwatch, organised by the West of London Astronomical Society at the Ruislip Lido. Given last nights experience of setting up in the dark, I decided to pick up the car a little earlier this time and get to the Lido whilst there was still some day light to be had. This made the whole process of setting up all the more easier. My wife, Gitanjali, also came along tonight and gave me a helping hand to setup as well as enjoying her time speaking to enthusiast members of the public and taking turns to look through all the different telescopes that were available on-site. Tonight I counted at least ten telescopes that were available to look through, ranging from the very small all the way up to large 12 inch reflectors and big Dobsonian telescopes. A couple of more people brought their laptops along and did some imaging with their specially adapted astronomy CCD cameras. These setups were certain good crowd pullers!

Word about the Spring Moonwatch event had certainly got around by now and a lot of families came to visit us. Mothers, fathers, relations and children were all coming down to take a look through the telescopes. Here’s an interesting anecdote. I called Anglian to give me a quote for double glazing a few days ago. The gentleman who came around to my house a few days ago was very fascinated by the site of my William Optics 110mm refractor telescope which was standing in the corner of the living room. I told him about the Ruislip Lido event and asked him to come along since he was so interested in telescopes. Well what do you know? Last night, he turned up with his two sons! The elder one was very taken by the whole experience and I suspect he wants his father to buy him a telescope. Moustafa Ali, the Anglian salesman, hails from Egypt and commented that where he had grown up as a child, he would venture out in to the desert at night and see so many stars. Now that he lives in London, he feels many people are missing out on the vista of space and stars that can be seen on a really dark and clear night. He hopes that through signing up to WOLAS and getting himself and his sons involved in astronomy, they too can discover the wonders of space. How wonderful!

Last night’s observing session certainly prompted a lot of questions from the members of the public who were attending. I spent considerable time explaining the life cycle of stars, the nature of binary star systems and the reasons why Saturn’s rings are so edge on to us right now. The green laser pointer I was carrying in my pocket came in very handy and allowed me to point out many constellations and stars in the sky. It was pleasant to meet some public who knew their way around the sky. I met a gentleman called Nat who told me his favourite star in the sky was Polaris in the constellation of Ursa Minor. He kept talking about Polaris and eventually plucked up the courage to ask me to point the telescope towards it. I swung my telescope over to that star and offered Nat to look through the telescope and he was awestruck at the site of his favourite star, even though all he saw was a single bright dot of a star. It’s amazing what floats different peoples boat. The cool part about looking at Polaris was explaining how it was a binary star and that there were two stars circling each other under the influence of their mutual gravity and then showing the two stars split through the telescope by inserting a much higher power lens. This prompted me to swing the telescope over to Mizar in the constellation of Ursa Major (The Big Dipper or The Plough) which is a really great double star to show anyone. Quite a lot of people were amazed by the site of the binary system.

Another favourite of the evening was the Plaiedes. To observe this cluster of stars, which I like to describe as a cosmic treasure chest of diamonds, I set up both the 110mm and 66mm telescopes to look at the object at the same time and inserted a 35mm lens in the 110mm telescope and a 40mm lens in the 66mm telescope. This allowed two different people to observe the same object at once which seemed to attract a lot of people around my telescope.

Another member of the public was fascinated by the notion of a binary star system so I gave him a brief guided tour of a few more binary star systems and started out by pointing out a particularly interesting system called Capella, the 6th brightest star in the northern hemisphere in the constellation of Auriga. Although it appears to be a single star to the naked eye, it is actually a star system of four stars in two binary pairs. The first pair consists of two bright, large stars, both with a radius around ten times the Sun’s, in close orbit around each other. The second pair, around 10,000 astronomical units from the first, consists of two faint, small and relatively cool red dwarfs. Just in-case you’re wondering what an astronomical unit is, it is a unit of distance often used by Astronomers to describe the mean distance of the Earth from the Sun. Therefore, 10,000 astronomical units basically means 10,000 times the distance from the Earth to the Sun.

At around 10pm, we all start to pack up. The night was a perfect conclusion to Spring Moonwatch and most definitely ended on a high note. I greatly look forward to next years Spring Moowatch event at the Ruislip Lido. Much appreciation and thanks go out to everyone at WOLAS who put the time in and effort in to organising this annual event.

You can read about the previous two days of Spring Moonwatch on my first and second write-ups.