http://news.bbc.co.uk/2/hi/science/nature/4278005.stm
Huge 'star-quake' rocks Milky Way
Astronomers say they have been stunned by the amount of energy released in
a star explosion on the far side of our galaxy, 50,000 light-years away.
The flash of radiation on 27 December was so powerful that it bounced off
the Moon and lit up the Earth's atmosphere.
.......
The initial burst of high-energy radiation subsided quickly but there
continues to be an afterglow at longer radio wavelengths.