Searching for the biggest stars in the universe

Of the billions of stars in the universe, the most massive play a crucial role but are the least understood. A major Leeds-led project is searching the skies to locate these elusive stars, and help us understand more about how the galaxies work.

“We know how big stars end – they explode as supernova and can form black holes – but we know little about how they’re formed,” explains Dr René Oudmaijer in physics and astronomy. “These stars play an important role in the evolution of galaxies by injecting large amounts of enriched material and energy back into the interstellar medium and powering spectacular phenomena like stellar winds and supernovae.

“Their strong radiation can evaporate the dusty particles that grow into planets, preventing new ones forming or perhaps even destroying them.”

Studies into these immense stars in their early years (up to a million years old) have been hampered by a lack of examples. The five-year project – the RMS survey – due to finish early next year will change that. “A good massive star is hard to find, said Dr Oudmaijer. “Before we started, only 20 of these stars had been discovered accidentally, and were therefore not representative of their class. We now have hundreds of good candidates to focus on.”

Tracing the stars is particularly challenging because they’re often hidden in the immense dust and gas clouds out of which they are formed. The astronomers have been using advanced infra-red technology and world-class telescopes across Europe, Asia, China, Australia, the USA, Hawaii and Chile to track potential candidates and confirm which are the genuine article.

The team, which also includes astronomers from Liverpool John Moores, the Purple Mountain observatory in China and the Australian University of New South Wales, hope their findings will shed light on how these elusive stars form and influence their environment and neighbouring planets.

For more information on this and other projects currently being undertaken by the astrophysics group, see their website.

Photo: Dr René Oudmaijer and Dr Stuart Lumsden