Rahul Sharma (Editor)

GRB 080916C

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Other designations
  
GRB 080916C

Date
  
16 September 2008

Constellation
  
Carina

Event type
  
Gamma-ray burst

Duration
  
23±1 minute

Instrument
  
Fermi Gamma-ray Space Telescope

GRB 080916C is a gamma-ray burst (GRB) that was recorded on September 16, 2008 in the Carina constellation and detected by NASA's Fermi Gamma-ray Space Telescope. It is the most powerful gamma-ray burst ever recorded. The explosion had the energy of approximately 5900 type Ia supernovae, and the gas jets emitting the initial gamma rays moved at a minimum velocity of approximately 299,792,158 m/s (0.999999c), making this blast the most extreme recorded to date.

The energy comparison with a supernova ignores that most of the energy of a supernova is carried away in the neutrino burst. The total isotropic energy of GRB 080916C is estimated at 8.8 × 1047 joules (8.8 × 1054 erg) (the oft quoted 4.9 times the sun’s mass turned to energy) and should be jet-corrected to a much lower actual energy output due to the narrow angular width of the actual bursting jet. Thus it would be significantly less than the energy of a supernova neutrino burst, but is about equal to the energy in a supernova’s material explosion. Also, the peak energy flux of GRB 080916C is significantly less than a number of other GRB’s, such as GRB 080319B which peaked at nearly 1044 watts (1051 erg/s) in visible light alone. However, the total energy flux of the very long duration GRB 080916C is higher than any other measured GRB to date.

The 16.5-second delay for the highest-energy gamma ray observed in this burst is consistent with some theories of quantum gravity, which state that all forms of light may not travel through space at the same speed. Very-high-energy gamma rays may be slowed down as they propagate through the quantum turbulence of space-time.

The explosion took place 12.2 billion light-years (light travel distance) away. That means it occurred 12.2 billion years ago—when the universe was only about 1.5 billion years old. The burst lasted for 23 minutes, almost 700 times as long as the two-second average for high energy GRBs. Follow-up observations were made 32 hours after the blast using the Gamma-Ray Burst Optical/Near-Infrared Detector (GROND) on the 2.2 metre telescope at the European Southern Observatory in La Silla, Chile, allowing astronomers to pinpoint the blast’s distance to 12.2 billion light years.

References

GRB 080916C Wikipedia