London, Jan 11 (IANS): Astronomers have found that repeated mysterious fast radio bursts -- that are being flashed from more than 3 billion light-years away -- may be coming from a dense stellar core called a neutron star near an extraordinarily powerful magnetic field, such as one near a massive black hole.

Fast radio bursts, or FRBs, are intense pulses of radio waves lasting just milliseconds that can give off more energy in a fraction of a second than the sun does in hours, days or weeks.

Discovered first in 2007, the researchers estimate that there are 10,000 fast radio bursts happening per day, or a radio flash every 10 seconds, in each area of the sky.

These repeating bursts may come from a dense stellar core called a neutron star near an extraordinarily powerful magnetic field, which may be due to its proximity to a massive black hole in the galaxy or within a powerful nebula, the researchers said.

However, if it's near a massive black hole, that would explain the persistent radio source and create the right kind of environment. But the researchers aren't entirely confident that such a massive black hole would exist in a dwarf galaxy, Jason Hessels, Associate Professor at the University of Amsterdam, was quoted as telling CNN.

On the contrary, if it's within a powerful nebula, an interstellar cloud of gas or dust, it would also explain the persistent radio source and remain consistent with the fact that astronomers believe the source of the bursts is "young".

But it's a million times brighter than the Crab nebula in our own galaxy, which is already massively bright. How could the nebula be that bright?, Hessels said.

The findings support the idea that it's a neutron star or a pulsar, a highly magnetised and rotating neutron star.

The fact that the source throws out short bursts, ranging from 30 microseconds to nine milliseconds, supports a source that is just over six miles across. That's the right size for a neutron star, the researchers reported in the paper published in the journal Nature.