Derby and District Astronomical Society

IYA 2009 - Moonwatch at Herstmonceux - Sunday 25th October 2009

Article and Pictures by Chris Newsome

What better way to take part in the Moonwatch of October 2009 than at the home (or former home) of the 98” Isaac Newton Telescope, namely Herstmonceux, Sussex. A wonderful opportunity to look through some big telescopes – and I mean BIG. Looking at Albireo through the 7th largest refractor in the world was wonderful. On the weekend of 25th October 2009, I visited family in Kent with a view to going on to the observatory at Herstmonceux with my niece, Caitlin (the owner of my old Celestron C6-N). I had been keeping an eye on during the week and as the weekend got closer the weather was acting as forecast for the evening, namely clear! During the afternoon of 25th October, the weather omens were good and we enjoyed a fantastic sunset over Hastings on the Sussex Coast. The wind was strong and the sea very rough, but most importantly the sky was clear. I captured this view with a 10mm superwide Canon lens on my 400D.

When the sun had gone down, and we had enjoyed a mug of coffee and hot chocolate on the sea front, it was a short distance to Herstmonceux. We arrived at about 6pm and I could just make out the shadow of the dome of the INT against the deep blue sky – and then it happened! A poxy cloud over the site was emptying itself of rain! That soon passed and there could be the whirring of the domes in the main complex as they were opened up and slewed into position. Now that the skies were completely dark it was time to go to the first of the big telescopes, namely a 30” reflector/spectroscope. What a beast of an instrument! Attached to it was a finder that puts most amateur telescopes to shame – a refractor of about 8” diameter. The moon through it was very bright and as spellbinding as when I first looked at it through a telescope more than 30 years ago. I had my LPI with me but due to the fact that they were using 2” eyepiece mounts, I couldn’t use it, so the next best thing to hand was the good old mobile phone. The distortion in the photograph was due to me not being able to get the mobile phone properly lined up with the eyepiece.

After discussing the technicalities of how the spectroscope light path worked, it was time to move on to the 27” refractor in another dome. This utilised, as a finderscope, a 12” refractor! When inside the dome of the 27”, the scope was slewed to Albireo in Cygnus. Due to the varying ages and heights of the assembled people in the observatory to view the sky, the telescope mount was lowered to allow people to look directly through it or the 12” refractor. When I say the mount was lowered, what I really mean was that the floor was raised! A weird sensation! Who was moving – us or the scope?! Albireo through the 27” was, well, indescribable. I have never seen such a sharp point of light produced by a telescope as those stars were. And to further confirm the optics of the telescope, it was then slewed to M13. It was incredibly bright through the 27”. I say 'it', I really mean they. Because when you looked at M13, each and every star was visible individually, not as a hazy patch. Also the 27” refractor utilised a very novel GoTo system which should be patented. It is called Human Voice & Direction Version 1. What happens is that the telescope is connected to a computer and instead of the computer telling the scope where to go, the observer manually slews the 7 tonne+ scope and a human watches the computer display and shouts out "left a bit", "right a bit", "up a bit", "down a bit", "STOP!" Hey presto, the scope is pointing at the desired object. Makes finderscopes unemployed! There were a couple of telescopes not in use on the night, although the observatory domes were open to the public. In one was the 36” Yapp reflector which towered overhead:

At about 9pm we left the site and as we did so, we went past the old 98” mirror used in the INT (the scope is now on the Canary Islands). What a colossal size that was. Perhaps the society should put in an offer for it and construct a telescope and observatory around it and put it at Brailsford :–

For Sale. 1x 98” Mirror, optical quality, in need of aluminising, good quality glass, would suit ambitious society. Offers Please. Purchaser must collect!!!!!

Chris Newsome