doi:10.1038/nindia.2013.141 Published online 24 October 2013
Researchers have discovered a young, small-diameter supernova remnant about 16,300 light years from the Sun . Supernova remnants (SNRs) are dramatic objects produced by the violent explosions of dying massive stars. When SNRs cool and collapse, they form interstellar clouds from which new stars and planets can form.
Previous studies have predicted that there should be more than 1,000 SNRs in the local group of galaxies. However, only 274 have been detected to date. The poor angular resolution of previous surveys did not allow them to detect small-diameter SNRs.
To overcome this limitation, the researchers used the Giant Metrewave Radio Telescope, which picks up radio waves emitted by distant celestial objects such as SNRs. The study found that the discovered SNR had a shell-like structure with non-thermal polarized emission. The surface brightness of its shell compares well with those of the youngest SNRs in the Galaxy. The researchers claim that the SNR is expanding in a typical interstellar medium — an aggregation of dust and cloud in the empty space between stars. The SNR has a linear diameter of about 12 light years and its estimated age is between 100 and 500 years.
SNRs are important since they distribute various elements in the interstellar medium. The Big Bang produced very little material besides hydrogen and helium, yet most of our planet is composed of heavier elements, such as iron and nickel. These heavier elements were produced inside stars, and during supernova explosions they were dispersed into the interstellar medium.