martes, 31 de julio de 2007

Veil Nebula Pierced by Hubble's Gaze

The image displays two characteristic features of the Veil Nebula: sharp filaments and diffuse patches, which correspond to viewing the supernova remnants from edge-on and face-on views, respectively. This image is a small portion of the Veil located in the western part of the Veil (to the left in the overview image). Credit: NASA/ESA/Hubble Heritage/(STScI/AURA)-ESA/Hubble Collaboration/Digitized Sky Survey 2

VIDEO: Supernovas, Beacons in the Night

Only 5,000 to 10,000 years ago, a star familiar to human observers detonated and burned with a brightness comparable to that of a crescent moon-an event visible even in broad daylight.

The dead star's name may be lost, but its shattered remains are known as the Veil Nebula or Witch's Broom Nebula. Now, the Hubble Space Telescope has given astronomers three extreme close-ups of the supernova remnants' wispy clouds of dust and gas still careening into space some 1,500 light-years away from Earth.

Astronomers released the cosmic snapshots today.

The biggest stars live the shortest lives because they burn their light fuel into heavy leftovers, often collapsing and bursting apart in catastrophic supernova explosions that can outshine a galaxy of stars, as the Veil Nebula's progenitor did.

When a star detonates, the explosive shock wave hurtles stellar remnants into space at about half the speed of light, forming a shell of gas and dust. The Veil Nebula's shell spreads over a viewing area as wide as six full moons in our sky, and it still glows with the energy of its violent cosmic birth.

The Hubble close-ups reveal the rope-like filaments of gas in the nebula, which resulted from enormous amounts of dusty debris plowing into gaseous surroundings. Thicker filaments of material result from viewing the supernova's shock wave edge-on, while more wispy and diffuse views correspond to a face-on view of other parts of the shock wave from Earth.

Such supernovas may not seem relevant to humanity, but in fact they are the basis of it.

The handful of explosions that occur in the Milky Way each century, as well as explosions across time in other galaxies, create most of the heavier elements in the Universe such as copper, mercury, gold and uranium. In our galaxy, the expanding shells of material eventually mix with others in the Milky Way and form the raw material for new solar systems with stars, planets and possibly life.