It happened long, long before the Sun and the Earth were born, and yet its spectacular sign only became visible to us Earthlings last Wednesday, March 19, 2008.
In another reminder of how helluva big the Universe is and how infinitesimally small we all are, US scientists announced the explosion of a star that happened 7.5 billion light years away from Earth. For the record, one light year is equivalent to 5.9 trillion miles. Just try to do the math, if you can, to translate 7.5 billion light years to miles or kilometers.
Since the universe is some 14 billion years old, this means that the picture of this super-gargantuan cataclysm has been on its way to us for half the age of the universe — which means that the planets and other bodies orbiting this star were blown to smithereens long before our Sun and our Earth came into being.
The explosion led to a gamma ray burst which was detected by NASA’s Swift satellite last Wednesday at precisely 2:12 a.m.
NASA scientist Neil Gehrels, chief of NASA’s astroparticles physics lab at Goddard Space Flight Center in Greenbelt, Maryland, said the visible glow from this burst was 10 million times as bright as a supernova at that same distance. No chance for a human eye to see such brightness though since we would have all been annihilated by even a millisecond fraction of that heat.
Gehrels said the gamma ray burst was bright enough “to be seen with the naked eye.” Unfortunately, no stargazer has yet reported having developed a stiff neck from trying to see the tell-tale sign from the nighttime sky.
But according to Penn State University astronomer David Burrows, the starburst would have appeared as bright as some of the stars in the handle of the Little Dipper constellation. But other astronomers said it appeared in the constellation Boötes.
Whatever or wherever, the 7.5 billion light years away phenomenon far eclipses the previous naked eye record of 2.5 million light years.
Burrows said the distance is roughly halfway to the edge of the universe.
Before it exploded, the star was about 40 times bigger than our sun. The explosion vaporized any planet nearby, Gehrels said.
Gamma ray bursts are some of the most violent and enigmatic events in nature. Astronomers surmise that they might mark the implosion of a massive star into a black hole, or the collision of a pair of dense neutron stars.
Note on photo:
The extremely luminous afterglow of GRB 080319B was imaged by Swift’s X-ray Telescope (left) and Optical/Ultraviolet Telescope (right). This was by far the brightest gamma-ray burst afterglow ever seen. Credit: NASA/Swift/Stefan Immler, et al.