Suggested Searches

APOD

Astronomy Picture of the Day

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

See Explanation. Clicking on the picture will download the highest resolution version available.

A Slow Explosion

Explanation: 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 wind y 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 GRB s include supernova or hypernova explosions from massive stars, possibly ones with similarities to Wolf-Rayet stars .

Date March 25, 2003
Credit Credit: Y. Grosdidier ( U. Montreal ) et al., WFPC2 , HST , NASA
Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (UMCP)
A service of: ASD at NASA / GSFC,
NASA Science Activation & Michigan Tech. U.