The collision of two stars, a new find for Astrophysics

Angel A. Aponte

Astronomers observed a massive explosion last year, in a galaxy located 300 million light years from Earth, this was interpreted as a supernova others already known: the bursting of a white dwarf star-indeed, compact the waste of a star like the Sun that has exhausted its fuel, which has been swallowing gas from a companion star to explode herself.

However, some properties of this SN2006gz scientists raised the suspicion of the Center for Astrophysics Harvard-Smithsonian, and began to investigate further the supernova. The suspicions were well founded, since Malcolm Hicken and his colleagues have discovered that what occurred was SN2006gz titanic flash of the collision and explosion of two white dwarfs orbit twins who were in each other and drew close to colliding.

The trace of hydrogen or its absence in the spectrum of light from the explosion is the first track following the supernova astronomers to catalog the group I-a white dwarf that swallows matter from a companion star to explode-and group II -- and very massive star that collapses short-lived when it consumes its fuel and explodes. In group II is detected traces of hydrogen in group I, as SN2006gz, no.

So, this supernova was in group I, in particular Type Ia, but Hicken and his colleagues, also identified and well marked footprints-carbon and silicon in the field which she wore to the outbreak. The presence of these elements in the layers of matter of white dwarfs that shoot out in the explosion is a key feature predicted in theoretical models of the mechanism of collision and explosion of two of these bodies.

This discovery has been cautiously cosmologists who use the stars of the first group as indicators of distances of the universe. It was with this type of star that was discovered some years ago, the accelerating expansion of the universe, but with the explosion of this white dwarf, indicates that not all stars of the first group are equal, and can induce an error in the measures cosmic distance.