J. Brit. Astron. Assoc., 110, 1, 2000, p.52-53

CCD at the RAL where ACE beams to NOAA

Speakers at the CCD Symposium. From left to right: Guy Hurst, Andrew Elliott, Roger Pickard, Nick James, Ron Arbour, Bob Neville, Terry Platt, Richard Miles, Steve Foulkes and David Briggs. (Photo by Pete Seiden)

The Symposium was held at the Rutherford Appleton Laboratory (RAL) near Oxford, and attracted about 60 participants. It was originally planned and set in motion by Ron Arbour, but due to personal circumstances he was forced to drop out and hand the reins over to Dr Bob Neville, who did a formidable job in a very relaxed and easy manner. Eight speakers seemed far too many for one day, but Bob kept each short and to the point, to make the day an event to remember.

Dominating the Rutherford Appleton skyline is the 12-metre S-Band dish that monitors the ACE satellite. ACE - the Advanced Composition Explorer - is a solar physics mission that carries an experiment provided by NOAA (the US National Oceanic and Atmospheric Administration) to monitor the solar wind. ACE transmits data continuously, which is picked up by three ground stations spaced 120 degrees apart in longitude, providing almost round the clock coverage. The 12-metre dish is one of these three stations which then sends the data to NOAA at Boulder, Colorado, for processing and publishing on the World Wide Web. In this way, solar wind measurements taken 1.5 million kilometres from the Earth are available within a few minutes to provide early warning of terrestrial disruptions that could cause communication and power failures.

Against this backdrop, the eight speakers passed on their knowledge in a very relaxed atmosphere. After welcoming the large audience to the meeting Bob Neville announced that he had a presentation to make. A somewhat surprised Ron Arbour seemed very pleased to receive a slate plaque carved with SN 1998 an, the designation of his very first supernova discovery, in recognition of his contributions during the past 20 years to the UK Supernova Patrol.

Richard Miles started the proceedings with a detailed account of the International Amateur-Professional Photoelectric Photometry organisation (IAPPP). This was formed in 1980 to promote collaborative astronomical research between amateurs, students and professionals by providing a forum to exchange practical information not normally discussed or published elsewhere. He described how equipment and techniques had evolved into the powerful systems of today with particular emphasis on the arrival of CCDs in amateur hands. Although a fairly demanding process, there are so many interesting objects available to amateur equipment that observers were urged to investigate and apply photometric techniques.

Terry Platt of Starlight Xpress gave an overview of the latest advances in CCD technology and how far this technology will advance in the foreseeable future at affordable prices for amateur astronomers. He was able to whet the appetite of those present with the specifications of the latest CCD chips, which will raise the quantum efficiency from the present 40% region, up to nearly 70%.

Guy Hurst of The Astronomer (TA) magazine welcomed the impact that CCDs have had on supernovae patrols, but regretted that 'ordinary' nova patrolling was being overlooked. He told the audience how statistically there should be about thirty novae per year brighter than about mag +9, and yet only 1 or 2 per year are discovered. He suggested that CCDs could be used to discover the remainder if only people were not too overawed by the technology. His own experience with this technology only began in August 1998 when he purchased his first CCD camera. He now uses an MX516 unit connected directly to a 135mm camera lens - which gives a 10° field of view. This combination records magnitudes down to 11, which he explained was ideal, as any lower would greatly increase the number of stars in the field and could decrease the number of novae found. He takes two exposures of each to eliminate errors and showed some excellent shots of M22 in Sagittarius, a difficult area to image due to its large southerly declination.

Dave Briggs has long been respected for his knowledge on computers and CCDs, but until his talk at this convention had remained in the background. Initial nerves soon gave way to an excellent presentation of some superb images of deep-sky objects taken with the Hampshire Astronomical Group's 24-inch Newtonian.

Andrew Elliott gave the technical specification of his image intensifier video camera system, before showing his 10-minute video of the highlights of 1998 Leonid meteor display. This stunning video was accompanied by howls and gasps from the audience as fireball after fireball swamped the projected image.

Nick James gave a detailed account of the manufacture and workings of modern CCD chips and described some of the pros and cons of the current technology used by amateurs. He concluded his talk by showing some of the very large CCD chips currently available, although the cost of each was generally above the 'disposable income' of most amateurs.

Roger Pickard raised everybody's interest with his wit and enthusiasm as he described his experiences of CCD photometry. He showed slides of his telescope and detailed how he had overcome the problems of precision guiding which are even more stringent in CCD observing with its often longer integration times. Roger, who is the new Director of the Variable Star Section and a member of the Pro-Am Liaison Committee, went on to describe a proposed new observing programme to monitor dwarf novae for eclipses which would involve both visual and CCD observers.

Steve Foulkes detailed his work towards perfecting an automatic supernova patrol image acquisition system. He described the hardware, both computer and telescopic, as well as his ingenious software contributions to automatically identify supernova images. Although Steve has yet to discover his own supernova using this system, Mark Armstrong has proved its worth with his two recent discoveries (1999eg and 1999eh).

It only remained for Bob Neville to thank all the speakers and the attentive and appreciative audience for all of their contributions to this memorable day. Particular thanks were also given to the management and staff of the RAL for organising the facilities and providing such an excellent venue in truly magnificent surroundings.

Pete Seiden (Nightlife) and Bob Neville

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