from the you-would-be-blue-too dept.
Detecting the universe's earliest stars may be possible by looking for the supernovae of such stars, which should produce a color similar to the explosion of extremely metal-poor stars:
Similar to all supernovae, the luminosity of metal-poor supernovae shows a characteristic rise to a peak brightness followed by a decline. The phenomenon starts when a star explodes with a bright flash, caused by a shock wave emerging from its surface after its core collapses. This is followed by a long 'plateau' phase of almost constant luminosity lasting several months, followed by a slow exponential decay.
The team, [led by Alexey Tolstov from the Kavli Institute for the Physics and Mathematics of the Universe], calculated the light curves of metal-poor blue versus metal-rich red supergiant stars. The shock wave and plateau phases are shorter, bluer and fainter in metal-poor supernovae. The team concluded that the colour blue could be used as an indicator of a first-generation supernova. In the near future, new, large telescopes, such as the James Webb Space Telescope scheduled to be launched in 2018, will be able to detect the first explosions of stars and may be able to identify them using this method.