A solar flare is a sudden, rapid, and intense explosion on the surface of the Sun. (Photo: Nasa)
Source : India Today
Sun, which is a source of energy, at times could be the centre of deadly radiations hurled towards us. One such flare exploded on July 3, from a sunspot called AR2838. The solar flare, the largest since 2017, caused a radio blackout, the Space Weather Prediction Centre said.
The sunspot AR2838 burst through the surface of the sun unleashing the strongest solar flare in four years, an X1.5-class explosion. The sunspot, which is now gone, occurred over the star’s northwestern limb and is likely to move towards the far side of the Sun in the next couple of weeks.
The X-class solar flare ionized the top of Earth’s atmosphere, causing a shortwave radio blackout over the Atlantic Ocean.
Known for damaging equipment and electrical transmissions, the July 3 flare did not disappoint as it produced a radio burst, an ionospheric disturbance, a surge of electrical currents in the ground, and a deflection of local magnetic fields. According to reports, the flare led to ionization of the top of Earth’s atmosphere and caused currents to flow 60 km to 100 km above the planet’s surface, altering the polar magnetic field.
What is Solar Flare?
A solar flare is a sudden, rapid, and intense explosion on the surface of the Sun that happens when massive amounts of energy stored in magnetic fields are suddenly released. The explosion emits radiation across the length and breadth of the universe, hurtling them towards planets in the solar system. These radiations contain radio waves, x-rays and gamma rays.
According to Nasa, the energy released by this explosion could be equivalent to millions of 100-megaton hydrogen bombs exploding at the same time. However, it is just one-tenth of the total energy emitted by the Sun every second. There are three stages of a solar flare: first, the precursor stage, where the release of magnetic energy is triggered with soft X-Ray emissions. The second stage, named impulsive, is when protons and electrons are accelerated to energies equivalent to a million electron volts. The third stage is the gradual build-up and decay of the X-Rays.
The duration of these stages can be as short as a few seconds or could extend up to hours.
Types of solar flares
Scientists classify solar flares based on their X-Ray brightness and are categorised into three types. The solar flare that erupted on July 3 was an X-class flare, which is the biggest. These types of flares have the capability of triggering radio blackouts. The medium class flares are named M-class and affect Earth’s polar regions. Meanwhile, the smallest ones are C-class flares with minimal effects on Earth.
Isro had recently observed around 100 microflares, providing new insights about coronal mass heating on the Sun. The corona emits ultraviolet X-rays and consists of ionised gas at temperatures exceeding 2 million degrees Fahrenheit.