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Can you imagine it? On the same night that I received numerous text messages about GRBs, one goes off that you could have seen with your naked eye!

It was the second GRB to happen on March 19, 2008, so it gets the moniker GRB 080319B. It was first detected by Swift, as these things usually are.

But get this! At least three telescopes were observing the field just before the GRB went off! RAPTOR observed the field for an hour before it went off. The REM telescope in Chile observed the field at least 100 seconds before it went off. And the Pi of the Sky observed it sixteen seconds before it went off.

That’s not all! Pi of the Sky has this sweet animation of the GRB.

The peak magnitude of the GRB in the optical wavelengths was around 5.6, meaning if you had a dark sky and were looking at the right place, you could have seen it. You wouldn’t have seen it for very long, as it faded below 6th magnitude in a few seconds, but you could have seen it.

Further analysis seems to indicate that the GRB has a redshift of 0.937, which means that it’s about 7.5 billion light years away. Billion! The farthest object we can normally see with our naked eye is the Andromeda Galaxy, and it’s only 2.5 million light years away. This flash of light came three thousand times farther than that!

Phil Plait has an excellent bit on how bright GRBs are:

Imagine a one megaton nuclear weapon detonating. That’s roughly 50 times the explosive yield of the bomb dropped on Nagasaki. Devastating.

The Sun, every second of every day of every year, gives off 100 billion times this much energy. That’s every second. A star is a terrifying object.

In the few seconds that a gamma-ray burst lasts, it packs a million million million times that much energy into its beams. In other words, for those few ticks of a clock the GRB is sending out more energy than the Sun will in its entire lifetime.