Exploding Neutron Star

Mick Ohrberg writes "According to NASA News, scientists at NASA and CITA are watching a neutron star (4U 1820-30, 25,000 light years from Earth) explode. Or rather - watch an explosion happen just a few miles above the surface of this immensely dense body. What happens is that matter (mostly helium) from a companion star is by the gravity of the neutron star and collected on the surface until a layer is formed and sufficient pressure is generated. This will cause the helium to fuse into carbon and other elements, releasing enormous amounts of energy in the X-ray band. The event was caught using NASA's Rossi X-ray Timing Explorer. More details can be found here."

Comments

Some amount of energy...

[ControlFreal]

From the article:

It poured out more energy in three hours than the sun does in 100 years

Given that the sun produces about 3.8e+26 Watt, and that a year contains about 3.15e+7 seconds, the explosion comes down to a total energy release of about 1.1e+36 Joules.

Still, this is puny compared with a gamma-ray burst: in 60 seconds, that yields about 10e+45 Joules.

It's one kind of nova, not a supernova

[Spamalamadingdong]

A supernova is the event which creates the neutron star in the first place. At least one kind of nova is associated with neutron stars; I am not enough of an astrophysics geek to be sure if the term is also associated with flares from unstable normal stars, but I would suspect so (anything that brightens enough to be a "new star" would be a nova in the old nomenclature).

Our own sun is much to small to form a neutron star. When it shedds the outer gas layers it will form a white dwarf that eventually will turn into a cold iron ball.

It'll be a carbon ball, not iron; the Sun does not have enough mass to begin carbon fusion and create signficant amounts of heavier elements. It will begin the red-giant phase when it starts fusing helium (which happens when hydrogen fusion no longer generates enough heat to keep the core from contracting further) and die when it runs out.