NASA’s little satellite that could, Swift, recently celebrated its seventh year in space. It blasted into orbit on November 20, 2004, starting a mission that would increase our understanding of the most violent events in the universe, and shatter cosmic distance records.
I wrote about Swift six years ago, on the first anniversary of its launch, and the funny thing is not a whole lot has changed except for the numbers. It’s still going strong after 2500+ days in orbit, and instead of dozens of gamma-ray bursts seen after one year, now it’s seen well over 600. Gamma-ray bursts are the mind-numbingly violent explosions of stars that signal the births of black holes, and each event releases as much energy in a few seconds as the Sun will over its entire lifetime. Happily, the Earth is nowhere near any potential GRB candidates (the nearest is about 7500 light years away, far enough that any damage it could do to us would be relatively mild), but if one were, say, 100 light years away, it would cook us like a whelk in a supernova.
Observing GRBs is Swift’s primary mission, and it’s performed outstandingly. It’s spotted what might be the most distant cosmic explosions ever seen, at 13.14 billion light years away from Earth. It saw the brightest GRB ever detected. But it’s also surveyed the sky, looking at high-energy light from sources near and far. It’s mapped our nearby galactic neighbors the Andromeda (shown above) and Triangulum galaxies in ultraviolet. It’s even observed near-Earth asteroids.
You can see the latest GRBs seen by Swift online, and there’s also a fun little iPhone/iPad app you can download that shows you Swift info, including the latest GRB detected and where Swift is in its orbit over the Earth.
I worked on Education and Public Outreach for Swift for many years, and it’s really nice to see it still pumping out fascinating and important science. Happy birthday to Swift and congratulations to the Swift team!
Image credits: NASA; Image credit: NASA/Swift/Stefan Immler (GSFC) and Erin Grand (UMCP)
If I had a TARDIS, you know the first thing I would do is go see what a supernova looks like up close. I’ve even tossed around the idea of a little fanfic… but Megan Argo beat me to it. She’s a radio astronomer at the Curtin University of Technology in Australia, and she wrote up a cute and engaging account of The Doctor and Martha witnessing an unusual exploding star (an audio version of the tale is available too)
The cool thing is, the story she wrote is actually part of a real event: the explosion of supernova SN2007gr, the death of a massive star. 2007gr was a Type Ic supernova, which is a star much more massive than the Sun, but has lost the majority of its outer layers over time due to a super-stellar wind. The core is basically all that’s left, and when it runs out of fuel it collapses and then explodes.
2007gr was seen to have gas screaming away from it at almost half the speed of light, far faster than is typical for an exploding star. That means that the gas was focused into twin beams, probably shaped that way by the material swirling around the newly-formed black hole at its heart that formed in milliseconds after the collapse. It wasn’t strong enough to be a monumentally violent gamma-ray burst, but it instead a sort-of hybrid object, one part normal supernova and one part GRB. We’ve known for some time that there is a connection between the two objects, but the actual events are difficult to study because they’re uncommon. Supernova 2007gr is a rare opportunity to study one in detail.
But not as much detail as we could see if we had a time machine. Oh Doctor, there are some many things you could show us. But, I suppose, most of the fun is in figuring it out for ourselves.
Image: SN: NASA/CXC/M.Weiss; TARDIS: BBC; composition: Megan Argo