Another spectacular sky-boom has gone off recently - this time the star EV Lacertae, a red dwarf off in the direction of the Lizard. It's only 16 light-years away, but red dwarfs are such featherweights that even that close it's invisible to the naked eye.
Apart from a few hours on April 25th, when it was more luminous than the Sun.
It was so bright in everything from X-rays to Infra-red that at least one orbitting telescope shut down in self-defence, no doubt with a scream of "AIEEE! My eyes!"
Unfortunately it went off during daylight hours here on Earth, so we miserable meat-based organisms didn't get to see much.
That sort of flare on the Sun would be bad for Earth. It's really
bad for any habitable planets of EV Lac, because they'd be orbitting so close that this flare would have heated them to about 1000°C
(Altho for a plausible
biosphere orbitting a pair of flare stars, see MEDEA
, editted by Harlan Ellison, and especially Larry Niven's contribution 'Flare Time')
More details on EV Lac, flares stars, and why flares on these piss-weak little stellar runts are thousands of times brighter than flares on the Sun, see Phil Plait's Bad Astronomy blog -http://www.badastronomy.com/bablog/2008/05/19/the-red-dwarf-that-roared/