Physicist looking to understand the Crab Nebula

(Edmonton) The discovery that a celestial light, thought for the last 30 years to be unwavering in its intensity—but is in fact prone to mysterious bursts of energy—has a University of Alberta researcher scratching his head.

Although physics professor Craig Heinke co-wrote a paper on the strange behaviour of the Crab Nebula, he's not sure why it began emitting huge flares. Last fall, two space-telescope satellites, the Italian AGILE and NASA's Fermi, detected uncharacteristic surges of gamma rays (high-energy light) coming from the Crab Nebula.

Heinke says the flares lasted just a few days, energizing particles to levels rarely seen since the first millionth of a second after the Big Bang. "We're seeing particles accelerated to energies 100 times larger than the Large Hadron Collider, to speeds just below the speed of light," said Heinke. The Large Hadron Collider is the particle accelerator near Geneva that researchers from around the world are using to find out about the universe's origins and the nature of matter.

The Crab Nebula, so called because an astronomer thought it resembled the pincers of a crab, is the remnants of a dead star that became a cloud of gas and high-speed particles. The supernova explosion that created it was seen in the night sky by Chinese astronomers in 1054. The Crab Nebula is 6,000 light years from Earth, but still bright enough in the visible light spectrum that even amateur astronomers can see it. However, Heinke says evidence of flaring in the nebula only shows up on equipment that measures light at the very high-energy level of gamma rays.

"It was the Crab Nebula's stability at those high levels of light that encouraged astronomers to use it as a reference point to calibrate their gamma-ray and X-ray telescopes," said Heinke.

Now that its stability is in question, Heinke says, researchers will focus more attention on the nebula using an international team of satellite telescopes. Heinke says that while nebulae have been linked to the formation of new stars, planets and even galaxies, the Crab Nebula is probably still millions of years away from that kind of transformation.

"The most interesting thing about the flaring from the Crab Nebula is the particle acceleration it produces," said Heinke. "Billions of dollars were spent to artificially create near-light-speed particle acceleration at the LHC, and now we can observe it happening naturally in outer space."

Heinke's co-written research was published online Jan. 6 in Science.

If you would like to make a tax deductible gift in support of Professor Craig Heinke's research, please click here.