The Swift Gamma Ray Burst Explorer was launched on November 20th 2004 by NASA as part of their medium-sized “MIDEX” program. Now the first thing you’re probably thinking is “why isn’t the name Swift in capital letters?” The answer is that Swift is not an acronym. It doesn’t mean anything (except that you’re supposed to think of a small, fast bird).
If you look at some of the early press releases about Swift, NASA were hopeful that it would last for the duration of its two year mission, and survey over 200 gamma ray bursts (GRBs). Now, 11 years later, and with over 1000 GRBs under its belt, Swift has exceeded all expectations and is still going strong.
Gamma rays are extremely high frequency emissions formed by the decay of atomic nuclei, and a burst of gamma rays is exactly what it sounds like: in a Universe where most things happen over millions of years, GRBs are astoundingly quick. Slow ones can take a couple of hours; but the quickest have been and gone in a few milliseconds. Also, there are only a few every million years in an average galaxy, which you might think would make them hard to spot, but fortunately they are so unbelievably powerful that the energy has no problem travelling the millions or billions of light years between the source and the detectors on board Swift.
Swift has observed some pretty unusual events over its lifetime, including the most distant GRB ever seen, an x-ray source right in the centre of the galaxy, and a two-week long blast of stellar flares from a red dwarf reckoned to be 12 times hotter than the centre of the Sun.