When working, it splits light into its component colours, to reveal information about the chemical content, temperature and motion of planets, comets, stars, interstellar gas and galaxies.

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The visible light from it was bright enough for George Djorgovski, Mark Metzger and Shri Kulkarni of the California Institute of Technology and their colleagues to analyse, and to demonstrate that it had travelled through a cloud of interstellar gas at least 10 billion light-years from the earth.

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This says that the exploding material (whatever it may be) races outwards and collides with interstellar dust and gas, producing radiation.

ECONOMIST: A symphony in gamma major

It is the hot gas molecules that act as the radiators and the icy mantles of the interstellar grains are the main reservoirs where the gas molecules can come from.

BBC: University of Nottingham

He chose this because the supernova that created it blew a giant bubble, known as the Vela nebula, out of the surrounding interstellar medium, and that bubble is big enough to stand in for the infinite sheet of gas.

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