Exploding Black Hole Observed -- More Energy in a Second than the Sun in a Billion Years

 

              


Gamma Ray Bursts are the brightest things to happen to the Universe since its beginning -- extraordinarily intense electromagnetic events releasing more energy per second than the sun does in a billion years, and basically an excuse for astronomers to use every awesome adjective they know. 
GRBs are an incredible demonstration of just how big a universe is: they're extremely rare, only a few per galaxy per million years, and we see about one a day. They're so interesting NASA launched a satellite just for them, the Swift Gamma-Ray Burst Mission -- a mission so advanced that "Swift" isn't even an acronym.  They just liked the word.

GRBs are bursts of plasma ejected from the poles of dying stars but Swift observed that the central jet engine causing this emission lasted longer than the burst, and sometimes far longer than previous models could explain (almost three days).  

Now scientists from the University of Leeds have put forward an explanation for how this intergalactically emitting dynamo could endure so long: it's eating a star.

By consuming a nearby star the black hole would be sucking up an enormous amount of matter, and if it's rapidly spinning (as many of these holes in spacetime are, a combination of concepts that really proves human language wasn't built for relativity) it can twist it all along the intense magnetic field lines being dragged around the event. The gigantic magnetic stresses involved are what give the burst its incredible energy, lasting as long as it takes for the entire star to be consumed.

Reminder:  this is not the plot from an episode of Voltron.  This is really happening, all over the place, and we have an actual robotic spacecraft up there watching them.  

The first gamma-ray burst to be seen in high-resolution from NASA's Fermi Gamma-ray Space Telescope was one for the record books. The blast had the greatest total energy, the fastest motions and the highest-energy initial emissions ever seen.

"We were waiting for this one," said Peter Michelson, the principal investigator on Fermi's Large Area Telescope at Stanford University. "Burst emissions at these energies are still poorly understood, and Fermi is giving us the tools to understand them."

This explosion, designated GRB 080916C, occurred at 7:13 p.m. EDT on Sept. 15, 2010 in the constellation Carina. Fermi's other instrument, the Gamma-ray Burst Monitor, simultaneously recorded the event. Together, the two instruments provide a view of the blast's initial, or prompt, gamma-ray emission from energies between 3,000 to more than 5 billion times that of visible light.

Nearly 32 hours after the blast, Jochen Greiner of the Max Planck Institute for Extraterrestrial Physics in Garching, Germany, led a group that searched for the explosion's fading afterglow. The team simultaneously captured the field in seven wavelengths using the Gamma-Ray Burst Optical/Near-Infrared Detector, or GROND, on the 2.2-meter telescope at the European Southern Observatory in La Silla, Chile. In certain colors, the brightness of a distant object shows a characteristic drop-off caused by intervening gas clouds. The farther away the object is, the redder the wavelength where this fade-out occurs. This gives astronomers a quick estimate of the object's distance. The team's follow-up observations established that the explosion took place 12.2 billion light-years away.

"Already, this was an exciting burst," said Julie McEnery, a Fermi deputy project scientist at NASA's Goddard Space Flight Center in Greenbelt, Md. "But with the GROND team's distance, it went from exciting to extraordinary."

With the distance in hand, Fermi team members showed that the blast exceeded the power of approximately 9,000 ordinary supernovae, if the energy was emitted equally in all directions. This is a standard way for astronomers to compare events even though gamma-ray bursts emit most of their energy in tight jets.

Coupled with the Fermi measurements, the distance also helps astronomers determine the slowest speeds possible for material emitting the prompt gamma rays. Within the jet of this burst, gas bullets must have moved at 99.9999 percent the speed of light. This burst's tremendous power and speed make it the most extreme recorded to date.
One curious aspect of the burst is a five-second delay separating the highest-energy emissions from the lowest. Such a time lag has been seen clearly in only one earlier burst.
"It may mean that the highest-energy emissions are coming from different parts of the jet or created through a different mechanism," Michelson said.

The Daily Galaxy via NASA/GLAST

Image Credit: image of GRB 080916C On Sept. 17, 31.7 hours after GRB 080916C exploded, the Gamma-Ray Burst Optical/Near-Infrared Detector (GROND) on the 2.2m Max Planck Telescope at the European Southern Observatory, La Silla, Chile, began acquiring images of the blast's fading afterglow (circled). Credit: MPE/GROND

Comments

[Mike Delaney]

I kinda agree. Black hole collides with star, but star isn't sucked up, it explodes. black hole velocities exceed speed of light. That is WHY we call them "black". When they hit, all kinds of ROCKS melt. If The Star (rock) is big enough, rocks scatter everywhere. We are seeing these ROCKS cool. Matter is still present.

[Mike Delaney]

This is a comment on COOLING stars. With age, star shows sunspot activity. If sunspots are Black star is burning to carbon. If brownish spots occur then Possible RED star.
Maybe star composed of elements with 2 different 1/2 lives. With time one element decays and burns red (brownish sunspots). It is COOLING. If it explodes it is because the "HOTTER element breaks crust VIOLENTLY.

[Mike Delaney]

Took another look at Picture. We probably have just witnessed the BIRTH of a solar system. This just connfirms my 1st comment.

[smartypants]

Mike Delaney
I am not saying you are wrong, but stars are made mostly of hydrogen and helium, neither of which can make a rock. I guess since I have never seen plasma cool it is possible it could become a rock. I am assuming you are thinking of lava cooling into rock for a comparison. But there is no lava on a star. I really think a star that exploded would become 95% gas and the rest dust. Also a solar system needs a sun (thats where solar comes in). A black hole in the center would be called some thing else. Details I know. Again, I am not saying you are wrong, just I disagree.

[Anonymous]

The title is misleading. The black hole isn't exploding, it's causing an explosion.

[Jaroslav Kourakin]

Still the black holes do have to explode, else everything will eventually be consumed in one supermassive black hole. That is stupid, I'm pretty sure there is a point where black holes cannot contain themselves and it is not when they have consumed the entire universe.

[Jaroslav Kourakin]

Actually, if I understand it correctly, this article says black holes are where mc2 finally happens, at a point where it will accelerate an object to the speed of light squared. Thus the light from these explosions are not the regular light otherwise consumed by the gravity of it.