NASA's Fermi detects gamma rays from solar eruptions located on far side of the sun - Watch

Image credit: NASA Goddard/YouTube

New Delhi: NASA's Fermi Gamma-ray Space Telescope has detected gamma rays - the most energetic waves of light on the electromagnetic spectrum – from solar eruptions located on the Earth-facing side of the sun.

Gamma rays are produced by the hottest and most energetic objects in the universe, such as neutron stars and pulsars, supernova explosions, and regions around black holes.

"Fermi is seeing gamma rays from the side of the sun we're facing, but the emission is produced by streams of particles blasted out of solar flares on the far side of the sun," said Nicola Omodei, a researcher at Stanford University in California, in a NASA press release. "These particles must travel some 300,000 miles within about five minutes of the eruption to produce this light."

Video credit: NASA Goddard/YouTube

This apparent paradox is providing solar scientists with a unique tool for exploring how charged particles are accelerated to nearly the speed of light and move across the sun during solar flares.

NASA says Fermi has doubled the number of these rare events, called behind-the-limb flares, since it began scanning the sky in 2008. Its Large Area Telescope (LAT) has captured gamma rays with energies reaching 3 billion electron volts, some 30 times greater than the most energetic light previously associated with these "hidden" flares.

These behind-the-limb flares occurred October 11, 2013, and January 6 and September 1, 2014. Scientists believe all three events were associated with fast coronal mass ejections (CMEs), where billion-ton clouds of solar plasma were launched into space.

Omodei presented the findings at the American Physical Society meeting in Washington on Monday, January 30. A paper describing the results will be published online in The Astrophysical Journal on January 31.