The discovery of the accelerating expansion of the Universe using Type Ia supernovae was awarded the 2011 Nobel Prize for Physics. However the cause of this acceleration is still not understood. In order to understand whether the acceleration is caused by some mysterious 'Dark Energy' that pushes the universe apart, or whether there is another explanation such as our incomplete understanding of gravity, more precise measurements of the geometry and expansion of the Universe are needed, using a range of different techniques that include new supernova surveys.
Supernovae of Type Ia are "standard candles", meaning that their intrinsic brightness is constant and so they can be used to measure distances in the Universe. In Oxford we are involved in several projects that aim to find and study supernovae in more detail and/or at larger distances, so that they can provide more accurate constraints on the cosmological parameters. These projects include the Supernova Legacy Survey (SNLS), the Palomar Transient Factory (PTF), The Public ESO Spectroscopic Survey of Transient Objects (PESSTO) and ESA's future Euclid mission.