Intro music.
As Swift begins its investigation of gamma-ray bursts,
NASA scientists are anxious to see if their origins lie in the explanations of three possible theories.
Ranging from simple to complex, all three theories have something in common:
the destruction of stars to form infamous black holes.
The first theory suggests a burst is triggered when a star's core collapses.
Millions of years before the collapse, the hydrogen fuel inside the core begins to wither.
Once the internal fuel supply is exhausted, the core implodes and creates a black hole.
Within seconds of its formation, tandem particle jets erupt from the black hole's center.
The twin jets rupture the star and produce a supernova explosion.
This stellar detonation in turn ignites the gamma-ray burst.
Like the previous "collapsar" theory, the supernova model also involves the implosion of a star's core.
As the star burns the last of its hydrogen, it swells into a red super-giant.
At the same time, the inner iron core implodes, compressing its atoms and raising the internal temperature by billions of degrees.
This rapid increase in temperature and pressure unleashes a devastating shock wave.
When the shock wave reaches the star's outer layers,
they are superheated and thrust out into space, resulting in a brilliant release of supernova light.
The final concept is known as the binary merger theory.
Perhaps the simplest of all the theories, it begins with a pair of neutron stars,
or a neutron star and a black hole orbiting each other.
The gravity between the two objects causes them to draw nearer and whirl at increasing speed.
The force of their gravitational attraction is so strong that it begins to distort their shape.
Before long, the two objects merge, producing a black hole and an eruption of gamma rays.