Polarisation technique
used to 'see' exoplanet

For the first time, astronomers have been able to detect and monitor the reflected visible light that is scattered in the atmosphere of an exoplanet. Employing techniques similar to how sunglasses filter away reflected sunlight to reduce glare, a team of scientists led by Professor Svetlana Berdyugina of ETH Zurich's Institute of Astronomy were able to extract polarised light to enhance the faint reflected starlight "glare" from an exoplanet. As a result, the scientists could infer the size of its swollen atmosphere. They also directly traced the orbit of the planet, a feat of visualisation not possible using indirect methods such as gravitational "wobble" detection. The exoplanet under study circles the dwarf star HD189733 in the constellation Vulpecula and lies 60 light years from the Earth. Known as HD189733b, the exoplanet is so close to its parent star that its atmosphere expands from the heat.