Sunday 17th November saw the BAA return to Bedford School for their ‘Equipment and Techniques’ section meeting. The day promised to be an interesting mix of talks, and was well attended with just under 40 BAA members making the journey from various corners of the UK.
Following introductions by David Arditti (Section Head) and BAA President Alan Lorrain, Tony Morris kicked off the day with his talk on using his DSLR for astrophotography. Tony took us through the techniques and equipment he uses to produce some wonderful images, and encouraged us all to get out with camera’s and shoot the sky! If you have a DSLR – or even a point-and-shoot – you are halfway there, as much of the software available to process the images is freely available.
Next up was Equipment Section Head David Arditti, taking us through his project at home to convert a cheap £100 shed into a functional observatory on his patio at home. It was very informative and David has some good tips for those of us who are thinking about such projects! He went on to demonstrate that you really don’t need to spend huge sums of money to get a functional observatory, but perhaps a very understanding partner is what is needed – David has 3 observatories!
BAA Vice President Callum Potter then described (for me at least!) some very interesting concepts of the programming language Python for astronomy work. In particular, he talked about the library of functions called AstroPy that has been specifically created to support a multitude of astronomical functions – from basic date/time conversions to complex statistical analysis. This is not for the feint-hearted but the concepts could be interesting for self-study in astrophysics!
<Note, I hope to use some of these into future web site functionality – watch this space!>
After an excellent brunch-style lunch provided by the School catering team, it was back to the talks! Keith Burrell had brought along his Mesu mount to demonstrate an innovative approach to installing the mount in such a way that allows even the most solid clay garden to accommodate a pier! The concept is of two steel plates, separated by a gap of approx 100mm. Passing through the plates are steel pipes, arranged at angles to form two A-frames with the steel plates, that are driven into the ground. The method provides a very solid foundation, with each plate being independently adjustable to ensure the pier can be perfectly leveled. Sadly, due to ill health, Keith is no longer able to take the project forward and is looking for someone to take the installation method forward and use it – all Keith would like in return is access to the image data so he can process it! Anyone interested in find more should reach out to the BAA.
Simon Kidd then talked about high precision timing for recording astronomy videos – especially important in his field of interest, that of asteroid occultations of stars. Windows computers are notoriously lax in their time-keeping – hopefully they are not used in critical applications – and even with a high speed internet connection, the time can drift by several minuted over a short period of time. The technical explanation is rather boring, but essentially the computer is usually doing other things other than checking the time! Simon has devised a method of timing using a modified CMOS camera, red LED and some fibre optic cable to insert a flash of light at precise 1-second intervals into one corner of the camera sensor. This means he is able to guarantee the time-coding on the video and thus be able to accurately compare observations. Using this method, it is possible for a group of observers to accurately distinguish the shape of an object from these timings!
Back to observatories for Richard Miles presentation on another novel idea for an observatory. After strict instructions from his wife that the observatory in the new home was not to be obtrusive, Richard set about designing the smallest observatory possible, that would house his large Paramount and 14-inch SCT instrument! Richard decided to use aluminium plates to construct the observatory, and after some very careful measurements and paper models to prove the concept, he set about the build! The design took the shape of the mount and telescope when both axis are horizontal – both level with the ground. The top section was made of two shells that could be slid apart, and then slid off internal runners before removed completely and placed out of the way. Closing the observatory was simply a case of locating the shell on its runner and sliding it into position. Another example of ‘necessity being the mother of invention’ and when finished, it was indeed unobtrusive and compact!
The penultimate talk was from Martin Lewis, a prominent planetary imager, discussing the problem of the ‘Edge Rind’. This is a phenomenon that gives rise to a bright ‘edge’ to the planet’s image, which then has a darker ‘shadow’. Martin discussed the various techniques used to try and determine the cause of this artefact – that research is still continuing. You can see more of Martin’s research on his web site – http://skyinspector.co.uk/mars-edge-artefact
Finally, Alan Dowdell introduced us to the Reverand Berthon, his dynamometer for measuring the focal length of eyepieces accurately, and the collapsible life-boat! Yes, you read that right!! Berthon was a Reverand that also ran an observatory and telescope making business (probably much to the Bishops annoyance) – he actually invented the Romsey-type of observatory – and the Berthon Marina still flourishes today.
It was a very informative and interesting day, some definite techniques to take away and try and certainly more research to be done!