Astronomers discover 'shooting stars' in the sun's corona

Shooting stars are normally comet debris or meteors that streak across the sky as they burn up in a planet's atmosphere, but on the sun, they are made of the sun itself.
John Loeffler
Solar astronomers discover ‘shooting stars’ on the Sun’s corona
Solar astronomers discover ‘shooting stars’ on the Sun’s corona

Patrick Antolin 

A team of European astronomers led by the Northumbria University in Newcastle, UK, have spotted a remarkable phenomenon taking place on the sun: ‘shooting stars’.

The sun itself is a star, but like shooting stars here on Earth, these aren’t actual stars, though those on the sun are technically closer in spirit at least. Whereas shooting stars on Earth are produced by space debris entering and then burning up in our atmosphere, shooting stars on the sun are produced by high-temperature solar plasma.

The European Space Agency’s Solar Orbiter (SolO) caught site of the phenomenon in so-called coronal rain. This is when the millions-degree solar plasma being ejected from the sun hits a relatively cooler spot in the outer layer of the sun’s atmosphere, the corona, and condenses similar to water vapor in Earth’s atmosphere turns into precipitation. These massive clumps of solar plasma are then pulled back into the sun.

“The inner solar corona is so hot we may never be able to probe it in situ with a spacecraft,” Patrick Antolin, an assistant professor at Northumbria University and the project’s lead author of a paper on the phenomenon that is set to be published in a special issue of Astronomy & Astrophysics as well as presented this week at the annual National Astronomy Meeting, said in a statement

“However, SolO orbits close enough to the Sun that it can detect small-scale phenomena occurring within the corona, such as the effect of the rain on the corona, allowing us a precious indirect probe of the coronal environment that is crucial to understanding its composition and thermodynamics. Just detecting coronal rain is a huge step forward for solar physics because it gives us important clues about the major solar mysteries, such as how it is heated to millions of degrees.”