It
won't be as spectacular as Tycho's Supernova of 1572 or Kepler's
Supernova which occurred some decades later and was visible in daylight.
However, a seemingly new star will appear in the constellation of
Hercules and should be as bright as the North Star. The nova is
predicted to happen before September 2024 in a binary system 3000 light
years away, made up of a dead white dwarf and ageing red giant. The
white dwarf, consisting of "star stuff" so dense that a teaspoon of it
would weigh five tonnes, is sucking material off the "nearby" red giant.
Every 80 years or so, the the material it accumulates reaches a
critical mass and a thermonuclear fusion reaction is sparked off, the
star lighting up so that it can be seen from Earth, 18 thousand trillion
miles away. In reality, because the star system is 3000 light years
away, the event really occurred 3000 years ago, the light taking this
length of time to reach us.This BBC article provides more details.
