A Slow Explosion
Why would a
gamma ray burst fade so slowly?
This behavior, recorded last October,
is considered a new clue into the cause of
gamma-ray bursts,
the most powerful explosions known in the universe.
The burst, first detected by the orbiting
HETE satellite
and later tracked by numerous ground-based telescopes,
showed an unusually slow and tumultuous decay in visible light.
Speculations on the cause of the
unusual light curve include a blast wave striking a
windy circumburst medium,
a blast wave energetically refreshed by a faster outgoing shock,
and non-uniformity in a fast moving jet.
Pictured above is the massive
Wolf-Rayet star WR124, a star itself undergoing a
slow explosion
by producing a very powerful but tumultuous
wind.
Popular candidate progenitor sources for
GRBs include
supernova or
hypernova explosions from massive stars,
possibly ones with similarities to
Wolf-Rayet stars.