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Big Boom by Bootes
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An explosion bigger than anyone has seen in recorded history happened a couple weeks ago and few seem to have noticed. There was March Madness, Democratic infighting, and Paris Hilton doing more nothing, but only a few humans on Earth were aware of what happened in the sky in the constellation Bootes.
It was there that a special satellite named Swift noticed just the faintest flash of light. But what a flash of light! If you had been out in the darkness away from the city lights and looked exactly in the right place at exactly the right time you too would have seen it - just barely.
How exciting, huh?! No? Well, actually it was! Let me tell you some more of the facts and then maybe you will feel sorry that you, too, weren't able to witness this extraordinary event.
Once astronomers got a quick bead on this transient flash, they were able to conclude that it was an elusive gamma ray burst (GRB). These phenomena are the most energetic group of explosions we know about, even bigger than the heavens' conventional weapon, the supernova. There are several possible models for what these critters might be, but the latest ideas make them out to be superduper supernovae.
The more common supernovae we've all heard about are the explosive deaths of stars. They go kaboom, we go "wow," life goes on.
But these gamma ray bursts seem to be supernovae on steroids, focusing all their explosive power and energy out two narrow poles instead of all over the place. If we happen to be in the sights of one of the poleblasts we get a face full of energy right before our face vaporizes. And there is enough energy in those bursts to wipe out life on earth if one of them occurs in our galaxy and is aimed our way.
Now back to our Big Blast from a couple weeks ago and why it was so astonishingly colossal.
When astronomers looked at the data, they discovered that this particular GRB was a ways away. Not thousands of light years away, not millions, but billions of light years away. About 7.5 billion to be precise.
To put things in a time perspective, this means the star went blooey billions of years before our own star and its planets (including Earth) were even born. And its light just reached us now.
To put things in an energy perspective, let's use our star for comparison. You can imagine that if we moved our blindingly bright sun farther away from us it would get dimmer. Move it about 40 light years away and it would be so dim we couldn't see it naked eye. That's just 40 little baby light years, about 240 trillion miles.
And yet we could see this bad boy from 7.5 billion light years away. Imagine how incredibly bright it had to be to be seen halfway across the known universe!
This is what amazed astronomers - but not many other humans - when GRB 080319B appeared in our skies. The amount of energy needed to be that bright from that far away was more than 2 million times greater than the already mind-numbing amount of energy from the brightest recorded supernova. That is inconceivable.
This is why astronomers, professional and amateur, would have been in heaven just to catch a faint glimpse of the light with their own eyes. It was an historical moment in the Realm of Astronomy.
But alas! That GRB is dead and gone. All we can hope for is another big one. But, please, not too big or too close, too energetic or too focused. We would like to live to tell the tale.
Until next time, clear skies!
Posted by Mark Ritter at 2008.04. 6 09:37 AM | Comments (0)
