Xmas with the stars

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Sussex astronomer is a rising star

Three new planets orbiting distant stars have been discovered by a team including CPES undergraduate Kevin Apps. They are the first planets to be discovered by a British-funded telescope and by a mainly British team.

"This project is giving us a very important first glimpse into how our solar system fits in with others," Kevin says. "It also gives us a perspective on ourselves in that our solar system appears to be quite unusual."

The three planets were discovered using the Anglo-Australian Telescope (AAT) in New South Wales, which began monitoring 200 stars in the Southern sky in 1998 and which is unusual in being able to detect much smaller planets than other telescopes.

Although these planets are too small actually to be viewed directly, the effect of their presence can be seen by the 'Doppler shifting' that their gravitational pull causes on the light from the star they are orbiting.

Viewing the light from the planets themselves will have to wait for new projects such as the Very Large Telescope Inteferometer (VLTI) now being built at the European Southern Observatory in Chile, NASA's Space Interferometry Mission (SIM) and the European Space Agency's Eddington and Darwin missions.

Of the three planets, the smallest - know as a 'hot Jupiter' - lies closer to its parent star than Mercury does to the Sun, and takes just three Earth days to complete its orbit around the snappily titled star HD179949. The second newly discovered planet has an orbit more like the Earth's and takes 426 days to orbit the star called epsilon Reticulum. However, the planet itself is not Earth-like and is thought instead to be a gas giant similar to Jupiter.

Completing the hat-trick is another large Jupiter-like planet taking a leisurely 743 days to orbit the mu Ara star. The team also discovered a 'failed' star - known as a 'brown dwarf' - orbiting another star, known as HD164427.

Since the first planet outside our solar system was discovered by a Swiss team in 1995, some 46 others have been found. None of them are capable of supporting life as we know it. Kevin has been involved in two previous planet discoveries, in 1998 and again in 1999. Now a finalist who hopes to go on to postgraduate study in the States, he says of the latest discovery: "This is obviously very good for my future career."

The other British members of the team are Alan Penny from the Rutherford Appleton Laboratory and Hugh Jones from Liverpool John Moores University. The project is funded by the UK's Particle Physics and Astronomy Research Council (PPARC), which funds research in particle physics, astronomy, cosmology and space science.

Finalist, Kevin Apps - part of the team who have discovered three new planets orbiting distant stars	The Anglo-Australian Telescope (AAT) in Siding Spring, New South Wales, which began monitoring 200 stars in 1998. See www.aao.gov.au for more details

The sky's the limit

Seb Oliver, an astronomy lecturer in CPES, has been invited to join a NASA mission to find out about life, the universe and everything that's going on up to 10 billion light years away.

The American space agency is launching a new orbiting observatory, the Space Infrared Telescope Facility (SIRTF), which will transfer data to space laboratories for analysis. The project, scheduled for 2002, is hoped to further our understanding of how stars and galaxies are formed.

Seb, along with other members of a team of mostly European scientists, will be studying that most feared of phenomena - black holes. These are massive areas in galaxies that have such a strong gravitational pull that light cannot escape.

"The belief now is that black holes exist in every galaxy," says Seb. "But we don't really know how they manifest themselves. An infrared telescope will pick up how these black holes work and tell us something about their history and how galaxies are being formed."

Seb's project, headed by US scientist Carol Lonsdale, is one of six selected out of 28 submitted to NASA for the mission.

"Although Carol is heading it, our team is largely European and I'm one of the three UK scientists involved," adds Seb, who was recently project scientist in infrared space study for the European Space Agency. The SIRTF project will build on his experience of mapping the skies to trace the history of star formation.

When the telescope is launched, his team will have 851 hours of observation time to cover an area of the sky equivalent to the space taken up by 500 full moons.

His work may involve what's happening 10 billion light years away, but Seb himself won't need to travel far from home. "I may visit the processing centre in California to begin with, but most of the analysis can now be done remotely," he says.