London & Munich

Keen to see the creation of a single European body with the clout to raise the funds needed for future large telescopes, Britain is this week opening negotiations about possible membership of the European Southern Observatory (ESO).

Based in Munich, the eight-member ESO is responsible for the construction and operation of a number of telescopes in the Southern Hemisphere, notably the Very Large Telescope (VLT) currently being built on Mount Paranal in Chile.

Halliday: ready to negotiate over fees. Credit: PPARC

Britain declined to join the organization when it was set up in 1962, claiming that it could not afford to do so. But Ian Halliday, the chief executive of the Particle Physics and Astronomy Research Council (PPARC), said last week that are now several reasons for becoming a member.

As well as giving British astronomers access to the VLT, membership of the ESO would allow the PPARC to become directly involved in the planning of major new international facilities, such as the proposed optical telescope known as the Overwhelmingly Large Telescope (OWL).

“In 10 years' time, if we want to build this type of facility, we need to be part of an organization such as ESO,” says Halliday. “We will not be able to afford to build it ourselves.”

Many members of the ESO, including its director Catherine Cesarsky, are happy for Britain to join. Franco Pacini, a member of the ESO council and director of the Arcetri Astrophysics Observatory in Florence, says: “No-one would deny how important it will be for ESO to have Britain as a member. It is a pity that [Britain] did not join long ago.”

But agreeing on the terms of entry will not be easy. The treaty setting up the ESO stipulates that new members must pay an entry fee as a contribution to the capital costs of the facilities they will be able to use.

In Britain's case, the entry fee would be £55 million (US$81.8 million). But Halliday says that, given the pressures on the UK science budget, paying such a sum is out of the question. “If they are insistent about us paying our full whack, we will not be able to get into ESO,” he says.

One ESO official says: “It is an unfortunate moment [for Britain to ask for special treatment] because ESO has just made a huge investment in the VLT, and member states may not be too happy about Britain joining without making a retrospective contribution.”

Cesarsky says that the ESO will enter negotiations with a flexible outlook. An offer in kind — for example, giving astronomers from ESO member states access to British telescopes at Paranal — would be considered seriously. But to suggest that the ESO would reduce the total value of the entry fee is, she says, “pure dreaming”.

Counting the cost: will Britain pay the price for access to Europe's Very Large Telescope? Credit: ESO

Even if the question of the entry fee is settled, there is also the issue of the annual payments, which would currently amount to £12 million a year. Without a significant increase in government funding to cover this sum, there would have to be cuts in other parts of the PPARC's budget.

Some of the money could be found, for example, by closing some of Britain's existing telescopes on La Palma in the Canary Islands. This prospect is worrying astronomers working on the facilities. There is also concern from particle physicists that covering a commitment to the ESO could be achieved by taking money away from accelerator research.

But the importance to British astronomers of joining the ESO was underlined in a report, Unveiling the Universe, published by the PPARC last week. It lists joining the ESO as high among its priorities. Reflecting the priorities of the PPARC's astronomy panel, the report suggests that the research council should seek an extra £39 million from the government over two years.

Halliday is not only confident of success in his negotiations with the ESO, but also optimistic that his efforts to build closer European collaboration will be received sympathetically in Whitehall. “ESO is currently not a well funded organization,” he says. “They probably have more telescopes than they can afford. Somewhere in there is a potential for negotiation.”

However, Cesarsky says that the ESO is not so strapped for cash that it needs to compromise to suit Britain's pocket. “Britain knows what the conditions are for joining,” she says.