Dr. Christopher ToutJohn Couch Adams Astronomer
Institute of Astronomy
University of Cambridge
Type Ia supernovae are some of the brightest objects in the Universe. They are all very similar so their apparent brightness tells us how far away they are. They are used to measure the distance to very far off galaxies. Through their careful observation we have learnt that the Universe is not only expanding but is accelerating as it does so. But what are they? Their true nature remains elusive. Everything points to white dwarfs that explode close to their maximum mass. But how can white dwarfs grow? The simplest way is to give them a binary companion so close that material at its surface can be sucked off by the white dwarf. We know that such close binary stars exist but all seem to have insurmountable difficulties when it comes to growing the white dwarf to a high enough mass. New observations rule out many possibilities without giving much insight into the actual progenitors. So where do we stand and can we trust they are really accurate cosmological rulers?
An expert in the evolution of stars and interacting binary stars, Christopher Tout was born in Billericay, Essex, England. He studied Natural Sciences and Mathematics as an undergraduate at Emmanuel College, University of Cambridge where he went on to write a PhD on Binary Stars and Mass Loss at the Institute of Astronomy. After two years as a NATO Fellow at Lick Observatory in California he returned to Cambridge as a Research Fellow at Sidney Sussex College and moved on to a Science and Engineering Research Council Advanced Fellowship, as part of which he spent time at the Space Telescope Science Institute in Baltimore, the Konkoly Observatory in Budapest and made his first visit to Australia followed by an eight month stay at Monash University. Since 2000 he has been a Fellow of Churchill College, where he is now Director of Studies in Applied Mathematics, and he was appointed John Couch Adams Astronomer in the University. He continues to visit Australia regularly.