Quarks are subatomic particles that normally only associate in groups of two – producing short-lived mesons, or three – producing the protons and neutrons that make up the bulk of normal matter.
But some physicists say that when matter is crushed to extreme densities, it settles into a soup of individual quarks. A cubic centimetre of this new type of matter – dubbed 'strange' after one of the six types of quark – would weigh as much as a billion tonnes and would have the unusual property of converting any ordinary matter that touches it into more strange matter, releasing energy in the process.
The energy released by converting the core of a star into strange matter would cause an explosion called a quark nova, which Leahy and Ouyed argue has been observed for the first time in SN 2006gy.
In their picture, the event begins when a massive star blasts away its outer layers in an ordinary supernova explosion. In the process, the star's core collapses to become a dense object called a neutron star.
But the team argues that some neutron stars last only a short time because their magnetic properties cause their spin rates to drastically slow down. Because centrifugal force can no longer support the neutron star's core, it collapses even further, transforming into strange matter.
The transformation releases a tremendous amount of energy, blasting the neutron star's outer layers into space at close to light speed. The layers then slam into debris from the original supernova, creating an intense glow bright enough to explain the observations of SN 2006gy, Ouyed told New Scientist.
Tuesday, August 21, 2007
Brightest observed supernova could have created quark star