Dying star fires cosmic cannonball...

Tue, 06/22/2010 - 10:16 — Ben Gilliland

...and creates glorious stellar art

If stars were like humans, when they reached the end of their lives they would slow down, gradually shine a little less bright and then die quietly tucked away in a cosmic nursing home. Fortunately (for those of us who can enjoy the results) stars die in a slightly more spectacular fashion From white dwarfs and red giants, black holes to pulsars, a star’s death can result in an entire pantheon of interstellar weirdness. The beautiful image to right is the result of star that exploded as a supernova more than 5,000 years ago. The explosion created an artistic masterpiece painted with stellar gases and launched a cosmic bullet and an epic cannonball.

The bullet is a cloud of gas kicked out of the dying star at more than 2,200 kilometers per second. It may look small here but that little blob is actually emitting more than ten times our Sun’s total energy in X-rays alone. The cannonball is the super-dense remnant of the star itself, called a neutron star, which concentrates a mass greater than our Sun into a ball just a few kilometers across. A sugar-cube size lump of neutron star material (called neutronium) weighs about the same as every man, woman and child on Earth.

The neutron star is of a type known as an SRG (Soft Gamma ray Repeater) that periodically emits blasts of super-high-energy gamma rays. It is giving off so much energy that, if you were to replace our Sun with it, the radiation it emits would fry our planet in an instant – that’s despite it being so small it would be invisible from Earth.

The image is a composite of data taken of the supernova remnant N64 by Nasa’s Hubble Space Telescope and the Chandra X-ray Observatory. The cloud is about 30 light years (300trillion kilometers) across and the blue areas show gas heated to millions of degrees.