Diamond powder surrounds distant young stars

For decades, astronomers have been wondering what is the source of the mysterious microwaves that reach Earth from distant star systems in our galaxy. Now they think they have the “valuable” answer: they come from tiny diamonds that surround some stars as a diamond-shaped cloud.

The specific radiation, called “abnormal microwave emission,” originates from various points of the sky, but so far its source has been unknown.

Researchers from the United Kingdom, the US and Germany, led by astronomer Jane Gribs of the Faculty of Physics and Astronomy, University of Cardiff, Wales, who published the publication in the Astronomy Magazine “Nature Astronomy”, studied extensively – with telescopes on US and Australia – the infrared light coming from protoplanetary discs around stars.

Eventually they identified the emitted microwaves with the distinct “signature” of tiny carbon crystals, also known as diamonds, found inside the dust and the gases surrounding the newborn stars.

This dust and gas mixture is the protoplanetary disc, where the planets are gradually formed around a star. This hot disk is packed with organic molecules and provides ideal conditions for nanodiamonds. It is estimated that 1% to 2% of the total carbon in such a dish is converted into nanodiamonds.

Thanks to the high energy that these diamonds have, as they spin at high speed inside the protoplanetary disk, they emit radiation to the portion of the electromagnetic spectrum that corresponds to the microwaves. Such nano diamonds, each of which are hundreds of thousands of times smaller than a grain of sand, have often been found in meteorites that have fallen on Earth and can also be produced by industrial methods.

“We knew that some kind of particle is responsible for this microwave light, but the exact source was a riddle since it was first detected 20 years ago. With a Sherlock Holmes method, we excluded all other possible causes, and with great certainty we can now say that the probable cause for creating this microwave flash is the presence of nanodiamonds around young stars, “Grevens said.