British Astronomy - Large Telescopes
The research councils come under the UK Government’s Office of Science and Technology (OST), a trans-departmental government body housed in the Department of Trade and Industry (DTI) and reporting to the Minister of Science. OST gave the research councils university-oriented mission statements and set up governing bodies with members from the universities, whose number, power and influence were growing with the increase of tertiary education in Britain in the 1960’s and ever since. PPARC coordinates its interest in space science with other UK space interests through the British National Space Centre (BNSC), also a trans-departmental government bureaucracy housed in the DTI. There is no state-run executive space agency in Britain on the model of NASA in the USA, CNES in France or ASI in Italy. The philosophy in Britain is that space is not an end in itself, deserving a free-standing, executive space agency, but a tool that is used by agencies for whatever end that they have in view. BNSC represents the UK to other national and international space agencies and tries to ensure that the various space interests in Britain coordinate and talk with one voice.
In the 1960’s optical telescopes within Britain had reached the 36-inch (0.9-m) class at observatories at Cambridge, Edinburgh, Greenwich/Herstmonceux and St Andrews. The observatory with the largest range of facilities presently operating in Britain is probably the teaching observatory of the University of Hertfordshire, with several domed telescopes (the largest of 0.5 m aperture) and specialised solar and photographic laboratories. All these telescopes operate for undergraduate projects, bright star monitoring and public education. The University of London Observatory (Mill Hill) is similar. However, realising that cutting edge optical astronomy had moved on from most of the science that could be accomplished with this class of optical telescopes under the British climate, optical astronomers had already, in 1939, moved the Radcliffe Observatory to Pretoria in South Africa from Oxford (the historic building is now part of Green College and has recently been beautifully restored), building the 74-inch (1.9-m) telescope in Pretoria by 1948. With other telescopes from Cape Town, the Radcliffe Telescope was later moved to the Sutherland outstation of the SAAO in the Karoo Desert in 1974.
Meanwhile, British optical astronomers had proposed a large 100-inch (2.5-m) aperture British telescope. Because of its established position of power, it was the Royal Greenwich Observatory, under its then Astronomer Royal Sir Richard van der Riet Woolley (1906-86), which built the Isaac Newton Telescope (INT, 1967). Save in one respect, the INT did not satisfy the universities’ needs. During study overseas, university astronomers had used telescopes in good climates such as California and did not like sitting under cloudy skies at night in Sussex. Also they did not easily relate to the civil service style of operation of the telescope. The weak optical astronomical facilities in Britain during this epoch drove a number of British astronomers to other countries – particularly to the USA, South Africa and Australia.
The most influential use of the INT was to aid the development of astronomical instruments, in particular the very productive Image Photon Counting System (IPCS) developed at University College, London, by Alec Boksenberg. This was a model instrumental development from the research council point of view. The IPCS consisted of an image tube to amplify individual photons, whose image screen was transferred by a lens to a TV scanner and read out. The output signals were processed in a hardwired unit to sharpen the image and to turn the analogue image into an array of pixels counting individual photons. The image tube and TV scanner were commercial units, developed with industrial money based in the entertainment and communication industries. They were operated in regimes adapted for the astronomical conditions, e.g. low light levels. The lens was ingenious, procured by the academics and the processing unit was not that expensive to make but of high intellectual content. This model for development and procurement of astronomical instruments became the ideal one favoured by the research council. It exploited the industrial development, based on capital which was hugely more than existed in astronomy and much better able to absorb the development risk, and added high-value but relatively small-scale academic know-how, which not only successfully tackled the astronomical problems (such as quasar absorption line systems) but also widened the scope of application of the industrial devices, added to their capability and stretched the involvement of the engineers who built them.
A southern hemisphere facility had become important to the optical astronomers with an interest in the southern sky, including the Magellanic Clouds and the centre of the Galaxy, and to space astronomers with their all-sky capability, seeking to coordinate what they had found with optical results. They pressed for the establishment of the 4-metre Anglo-Australian Telescope (AAT) and its associated survey telescope, the 48-inch UK Schmidt Telescope (UKST), at Siding Spring Observatory in Coonabarabran (1972-4). The AAT was operated by an Australian Government agency set up for the purpose, the Anglo-Australian Observatory (AAO), with 50% British participation. The UKST was wholly British. Although the atmospheric qualities of Siding Spring left something to be desired, these two telescopes worked together as a highly productive pair – there is more to being a great observatory than the meteorological conditions alone, and that special something is exemplified by the scientific drive behind the use of the two telescopes. The magic ingredients for the AAO were its unique capability in a southern sky till then unexplored by a telescope of that aperture, its versatile instrumentation, especially its spectroscopic capability with electronic detectors (first Joe Wampler’s Image Dissector Scanner and then the IPCS), its rapid follow up of space discoveries and its fresh, young staff. At first the two telescopes operated as a closely collaborating but separately administered pair. They are now both within the Anglo-Australian Observatory.
The UK Schmidt Telescope produced all-sky atlases of the southern sky in several wavebands on 14-inch (35 cm) glass plates. These and similar surveys in both south and north have been digitised by plate-scanning machines – the APM (Automatic Plate Measuring Machine, now decommissioned) at Cambridge University and COSMOS and its successor SuperCOSMOS at the Royal Observatory, Edinburgh, whose outputs are catalogues of celestial objects categorised by position, brightness and shape (star or various kinds of galaxy) . Although they are being superseded by modern surveys like the Sloane Digital Sky Survey, the catalogues of photographic data remain of interest because of the associated intellectual capital, used in present-day British astronomy as the basis of numerous studies of the structure of the Galaxy and the universe.
At first infrared astronomy was an extension of optical astronomy, but as the technology improved and the detector sensitivity moved longwards specialist telescopes became necessary. British infrared astronomers sought out a high, clear site for the 4-metre United Kingdom Infrared Telescope (UKIRT, 1979), and with its pioneering scientific output the telescope called world attention to the unique properties of Mauna Kea, Hawaii. It continues to operate as a survey telescope. Later, the 15-m. James Clerk Maxwell Telescope (JCMT, 1987) pioneered millimetre astronomy on Mauna Kea because of its dry atmosphere, with its self-similarly deformable and active optics dish pioneering the use of the technique for optical-infrared telescopes. It too is to operate in survey mode, including with its trail-blazing camera, the Sub-millimetre Common User Bolometric Array (SCUBA, shortly to be replaced by a new generation SCUBA-2) and as part of the Smithsonian Array. It also has receivers to observe spectral lines. UKIRT and the JSMT operate as the Joint Astronomy Centre on Hawaii.
After the AAO was established in the south, British radio astronomers in particular pressed for an optical ‘northern hemisphere observatory (NHO)’ to follow up their radio observations made from Britain, citing their discovery of radio quasars 3C48 and 3C273 whose optical identification, including the discovery of the main interest of their high redshift, had been ceded to US astronomers in California. The ‘NHO’ came into being as the Observatorio del Roque de los Muchachos, developed in collaboration with the Instituto de Astrofisica de Canarias, its core of astrophysical telescopes, known as the Isaac Newton Group, created by the UK with the Netherlands equivalent of PPARC, the Organisation for Pure Research (ZWO), by the move in 1984 of the Isaac Newton Telescope from Sussex to La Palma in the Canary Islands. The then main telescope at the Roque de los Muchachos Observatory was completed in 1986, the highly productive 4.2-m William Herschel Telescope (WHT), now inevitably outperformed by 8-m. class telescopes, except in niche science. Even before the telescope was completed at an aperture that had been achieved by the USA some decades earlier, there was discussion about the scientific case for Britain to have access to 8 metre class telescopes.
The Royal Greenwich Observatory continued to operate the INT and WHT in La Palma but, having lost its main telescope to an overseas site, it was moved for a second time in 1991, from its country location in Sussex to the university environment of Cambridge. There was competition for resources between the two Royal Observatories (Greenwich and Edinburgh), particularly their rival and duplicative interests in two separate mountain-top observatories, and between them and the universities. The growing feeling that the overseas observatories would operate better if they were controlled locally meant that RGO and ROE progressively lost control of La Palma and UKIRT/JCMT respectively. This all led in 1998 to the closure of the Royal Observatories in Cambridge and Edinburgh.
The Royal Observatory, Edinburgh, was transformed into a combined UK Astronomy Technology Centre to make astronomical instruments. With the Institute for Astronomy of the University of Edinburgh, it occupies the site still called the Royal Observatory, Edinburgh. That ROE survives in a modified form while RGO was completely closed, and its building sold off, led to the episode of 1998 being identified as the ‘closure of the RGO’.
The Rutherford Appleton Laboratory also develops technology for astronomy, as for all the sciences funded by the research councils (as clear from the formal name of the whole organisation, namely the Council of the Central Laboratory for the Research Councils, CCLRC). The highly influential Starlink project was housed there. Its primary purpose was to provide from central PPARC funds interactive data-processing facilities (software, hardware and skilled manpower) for UK astronomers. The data were mainly observational data, obtained from both satellite and ground-based instruments. Starlink was founded about 1975 from an unexpected budgetary surplus and ceased operation in 2005, having effectively rendered itself obsolete by having educated the dispersed groups where it placed its nodes, and with many of its functions that linked the community supplanted by the growth of the Internet, which it helped pioneer.
Astronomical instrument development of high intellectual content is carried out in several university groups, in the IPCS model described above. Additionally, PPARC expects university-based groups to drive the procurement of large-scale astronomical hardware for the large optical telescopes in the international facilities (VLT, Subaru, Gemini, …) in a different model. This will consist of a university-based project office, to design and control the project, with manufacture in industry or in a central physics laboratory able to cope with the scale of the equipment. Although space instrumentation is presently of a size that can be built in a laboratory it seems probable that space instrumentation groups may have to move in the same direction as space satellites get larger.
Telescope making has had a long history in Britain, with the names of Hadley, Short, Gascoigne, Dollond, Graham, Cooke, Troughton and Thomas Grubb coming to mind. Grubb’s engineering works were originally located in Dublin, run by Thomas and then by his son, Howard, but in 1918 the telescope-making business was relocated to St Albans. On its acquisition by Charles Parsons, the son of Lord Rosse, the company was again relocated to Newcastle, as Sir Howard Grubb, Parsons & Co. Because of the difficulty of managing the ‘feast or famine’ cash-flow associated with infrequent, large telescope projects, the company was wound up after it had completed the William Herschel Telescope in 1985 to designs developed by engineers of the Royal Greenwich Observatory. When RGO was closed the telescope-making intellectual capital and some staff were transferred to Telescope Technologies Ltd (TTL), now the only large telescope making company in Britain, a company set up by Liverpool John Moores University through its Astrophysics Research Institute.
TTL built the Liverpool Telescope (LT), a 2.0-m optical telescope which began science operations on La Palma in 2004. The LT, owned and operated by Liverpool John Moores University (LJMU), is the world’s largest fully robotic telescope, making its own decisions on what to observe without human intervention, and its scientific goals are to monitor variable objects on timescales of years to seconds and observe unpredictable phenomena at short notice (gamma ray bursters, for example, where the intention is that it is triggered to observe by the SWIFT satellite). In an experimental set-up called e-STAR (e-Science Telescopes for Astronomical Research, a collaboration including LJMU and Exeter University) the LT is being operated with the Faulkes Telescope North (also built by TTL on Hawaii) as a prototype for an intelligent global observing network (RoboNet) for such phenomena. TTL is also building telescopes in India and China and has announced a contract for a further number to extend the intelligent global network of robotic telescopes.
The archives of the Royal Observatory were transferred to the keeping of Cambridge University and its historic memorabilia were returned to Greenwich, to the Royal Observatory, which has become an important centre for the public communication of astronomy within the National Maritime Museum. Meanwhile, on the abandonment by the Royal Greenwich Observatory of its site at Herstmonceux, the telescopes of the Equatorial Group (the largest, the 36-inch Yapp reflector) had been turned into the Observatory Science Centre for public science education, along the lines of the Norman Lockyer Observatory in Sidmouth, which evolved out of Lockyer’s privately owned observatory of telescopes (up to a 30-inch) when he resigned from the Solar Physics Observatory and retired to Devon in 1911.
All the large telescopes to which UK astronomers have access (save the MERLIN radio array) are multinational, with Britain partnering Australia, Canada, the Netherlands, South Africa, Spain, the USA and other countries. The largest include the two 8-metre Gemini Telescopes, the first opened in 1999 on Mauna Kea, with the second soon afterwards opened in Chile. Six British universities are partners in the 11-metre South African Large Telescope (SALT) currently being brought to full operation in Sutherland. The UK joined the European Southern Observatory (ESO) in 2002, after having been unable to join on grounds of expense and in a political climate of Euroscepticism, at its foundation. British astronomers became converted after ESO’s impressive project to establish the very powerful VLT of four 8-metre telescopes, and attracted by the follow-on project to establish the Atacama Large Millimetre Array (ALMA) in the Atacama Desert in Chile and the prospect of a European plan to build a very large optical-infrared telescope of the 50 metre class. Attempting to repeat the success of the pairing of the AAT and the UK Schmidt Telescope, the UK initiated the building at ESO’s observatory at Paranal of the Visible and Infrared Telescope for Astronomy (VISTA), a 4-m Wide-Field Survey telescope to undertake long-term targeted surveys (at first infrared) in support of southern hemisphere observing programmes on Gemini and the VLT. VISTA became part of the contribution made by the UK to ESO as a joining fee.
The cutting-edge facilities offered by ESO in the form of the VLT have been progressively taking the attention of Britain’s optical astronomers. Coupled with the cost of belonging to ESO, this has caused a progressive weakening of Britain’s activity in the smaller telescopes in which it has a share, for example a greater share of the responsibility for the telescopes in the Canaries is being passed to the Instituto de Astrofisica de Canarias. The IAC is in any case now completing the 10-metre Gran Telescopio on La Palma and is increasingly lifting its attention from its university centre at the heart of Canarian politics in La Laguna, Tenerife, towards the scientific operation of the Observatorio del Roque de los Muchachos, La Palma. It is also expected that Britain will have passed its share of the ownership of the AAT wholly to Australia by 2010. This is all regarded with genuine nostalgia and sentiment by everyone (this author included) but accepted, too, as the inevitable cycle of scientific innovation and re-innovation.