August 4, 2013 - NASA's Hubble Space Telescope
has detected a new kind of stellar blast called a kilonova, which happens when a pair of compact objects such as neutron stars crash together. Hubble observed the fading fireball from a kilonova
last month, following a short gamma ray burst (GRB) in a galaxy almost 4 billion light-years from Earth.
"This observation finally solves the mystery of short gamma ray bursts," says Nial Tanvir
of the University of Leicester
in the United Kingdom, who led a team of researchers conducting this research.
This sequence illustrates the kilonova model for the formation of a short-duration gamma-ray burst. 1. A pair of neutron stars in a binary system spiral together. 2. In the final milliseconds, as the two objects merge, they kick out highly radioactive material. This material heats up and expands, emitting a burst of light called a kilonova. 3. The fading fireball blocks visible light but radiates in infrared light. 4. A remnant disk of debris surrounds the merged object, which may have collapsed to form a black hole. Gamma
ray bursts are flashes of intense high-energy radiation that appear from random directions in space. They come in two flavors--long and short. "Many astronomers, including our group, have already provided a great deal of evidence that long-duration gamma ray bursts (those lasting more than two seconds) are produced by the collapse of extremely massive stars," explains Tanvir.
The short bursts, however, were more mysterious.
WASHINGTON, Aug. 3, 2013 PRNewswire-USNewswire -- NASA's Hubble Space Telescope recently provided the strongest evidence yet that short-duration gamma ray bursts are produced by the merger of two small, super-dense stellar objects.
(Logo: http: photos.prnewswire.com prnh 20081007 38461LOGO )
The evidence is in the detection of a new kind of...