thehindu.com Mar 27, 2016
Sun may produce devastating superflares, say scientists
A solar flare bursts off the Sun in this image captured in 2014. Of all the stars with superflares that researchers analysed, about 10 per cent had a magnetic field as strong as or weaker than the Sun's.
The Sun is capable of producing monstrous eruptions or ‘superflares’ that can not only break down radio communication and power supplies, but also affect Earth’s ability to support life, scientists say.
Earth is often struck by solar eruptions. These eruptions consist of energetic particles that are hurled away from the Sun into space, where those directed towards Earth encounter the magnetic field around our planet.
When these eruptions interact with Earth’s magnetic field they cause beautiful auroras.
When the Sun pours out gigantic amounts of hot plasma during the large solar eruptions, it may have severe consequences on Earth.
Solar eruptions are, however, nothing compared to the eruption we see on other stars, known as ‘superflares’.
Superflares have been a mystery since the Kepler mission discovered them in larger numbers four years ago. The largest observed eruption took place in September 1859, where gigantic amounts of hot plasma from our neighbouring star struck Earth. Telegraph system worldwide went haywire, and ice core records from Greenland indicate Earth’s protective ozone layer was damaged by the energetic particles from the solar storm. Researchers from Aarhus University in Denmark used observations of magnetic fields on the surface of almost 100,000 stars to show that these superflares are likely formed via the same mechanism as solar flares.
“The magnetic fields on the surface of stars with superflares are generally stronger than the magnetic fields on the surface of the Sun,” said Christoffer Karoff, from Aarhus University.
However, of all the stars with superflares that researchers analysed, about 10 per cent had a magnetic field with strength similar to, or weaker than, the Sun’s.
Therefore, even though it is not very likely, it is not impossible that the Sun could produce a superflare.
“We certainly did not expect to find superflare stars with magnetic fields as weak as the magnetic fields on the Sun. This opens the possibility that the Sun could generate a superflare,” said Karoff.
If an eruption of this size were to strike Earth today, it would have devastating consequences for not just all electronic equipment but also our atmosphere.
As a result, it will kill of our planet’s ability to support life. Evidence from geological archives has shown that the Sun might have produced a small superflare in 775 AD.