Strange rays from the sun
Our central star emits much more high-frequency radiation than expected. Is this due to unknown properties of the solar magnetic field - or to even more exotic processes?
For a good decade, astronomers have observed the proportion of our sun's radiation with the highest frequencies and smallest wavelengths. Now they are faced with a mystery: seven times more of this so-called gamma radiation reaches us than expected. And oddly enough, within the excess there is also a narrow gap - a near-radiative frequency range.
These and other curious phenomena may indicate unknown properties of the Sun's magnetic field. Brian Fields, US astroparticle physicist at the University of Illinois at Urbana-Champaign, comments on the discovery: "It is amazing that we are so spectacularly wrong about the sun, which we should actually understand well."
For the first time, solar researchers encountered the unexpected signals in the data from the Fermi space telescope. It has been in orbit since 2008 and scans the sky for sources of gamma rays from there. The more measurements the scientists got, the better they could make out details in the spectrum of solar gamma rays. "We kept finding surprises," says Ohio State University astronomer Annika Peter, co-author of a review published in March 2019. "It's the strangest thing I've encountered in my career." …
