MYSTERIOUS bursts of X-rays from the heavens might be the death cries of the
first stars to light the Universe. Astronomers in Italy suggest that X-rays
occasionally spotted by satellites might come from explosions of monster stars
that roamed space before galaxies formed.
These “X-ray transients” are similar to gamma-ray bursts—short flashes
of gamma rays thought to come from very massive stars as they explode and
collapse into black holes at the end of their lives. But the X-ray versions last
from 10 seconds to a few minutes—longer than gamma-ray bursts—and
the radiation has a longer wavelength.…
