A new radiation burst was recently produced by a dying star

Nov 22, 2013 10:32 GMT  ·  By

Experts with the Astrophysics Division at NASA, in Washington DC, say that a number of space- and ground-based telescopes were recently able to observe what could very well be the most luminous and energetic gamma-ray burst (GRB) ever detected. The multitude of observations revealed many details of how GRB work, but also challenges established knowledge on how these bursts behave. 

The detections occurred on April 27, 2014, when a massive explosion took place in a distant star within our galaxy. This explosion occurred as the core of the celestial fireball collapsed, after losing its ability to sustain nuclear fusion. In turn, this led to the formation of a new black hole.

The process was accompanied by a massively energetic radiation burst, named GRB 130427A. Three NASA satellites detected the event as soon as it occurred, as did numerous robotic telescopes on the ground. GRB such as this one are triggered when black holes release particle jets that drill through the outer layers of the stars that died to create them.

This “burrowing” process is responsible for shooting radiation bursts into the night sky at highly-relativistic speeds, of 99.999 percent the speed of light. GRB of this magnitude are extremely rare, thought to occur just once or twice every 100 years.

“We expect to see an event like this only once or twice a century, so we're fortunate it happened when we had the appropriate collection of sensitive space telescopes with complementary capabilities available to see it,” says the director of the Astrophysics Division at NASA, Paul Hertz.

Freshly formed black holes can emit light in the million-electron-volt (MeV) range, which is nearly half a million times more energetic than visible light. The new burst produced a peak energy of 95 gigaelectronvolts (GeV), which is many times more intense.

GRB 130427A was detected by the Gamma-ray Burst Monitor (GBM) on the Fermi Gamma-ray Space Telescope, by the Swift Gamma-ray Burst Mission, and by the Nuclear Spectroscopic Telescope Array (NuSTAR), which observed the sky in X-ray wavelengths.

Details of the object's location were immediately relayed to robotic observatories in the Rapid Telescopes for Optical Response (RAPTOR) Project, which is operated by the US Department of Energy's (DOE) Los Alamos National Laboratory, in New Mexico.

“The spectacular results from Fermi GBM show that our widely accepted picture of MeV gamma rays from internal shock waves is woefully inadequate,” University of Alabama Fermi team member Rob Preece explains.

“We thought the visible light for these flashes came from internal shocks, but this burst shows that it must come from the external shock, which produces the most energetic gamma-rays,” adds another member of the team, Sylvia Zhu from the University of Maryland in College Park.

Analyses conducted on GRB 130427A are detailed in four scientific papers published in the November 21 online issue of the journal Science Express, by the Fermi, Swift and RAPTOR teams. Data collected by NuSTAR appear in the latest issue of the journal Astrophysical Journal Letters.

Photo Gallery (3 Images)

Fermi LAT instrument data showing the GRB 130427A
Diagram showing how particle jets and gamma-ray bursts develop around newly-formed black holesSwift image of GRB 130427A, collected on April 27, 2013
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