Monday, March 19, 2007

Cosmic Explosions


Scientists have used the world's largest robotic telescope to make the earliest-ever measurement of the optical polarisation of a Gamma Ray Burst (GRB) just 203 seconds after the start of the Cosmic Explosion. This finding which provides new insights into GRB physics was published in Science on 15th March 2007.

Read more Robotic Telescope Unravels Mystery of Cosmic Blasts

Optical Polarisation - Optical light is part of the electromagnetic spectrum and, as such is a wave with an electric vector, or vibration direction, that is usually randomly orientated relative to the direction of travel of the wave - this is unpolarised light.

When the light is produced by electrons that travel in a well-organised field the electric vector of the emitted light keeps a preferred direction. This alignment causes the light to be polarised. Measuring the amount of polarisation of light therefore probes the presence and structure of any guiding magnetic field in the object that has emitted the light.

Incoherent Radiation and Polarisation
Linear polarisation; Circular polarisation; Elliptical polarization

New Mechanism For Cosmic Gamma Rays From Starlight Is Proposed
New form of matter-antimatter transformation observed for the 1st time.
The 2007 Cambridge Science Festival March 18 - 25

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