A solar flare is an explosion on the Sun that happens when energy stored in twisted magnetic fields (usually above sunspots) is suddenly released. Flares produce a burst of radiation across the electromagnetic spectrum, from radio waves to x-rays and gamma-rays. Scientists classify solar flares according to their x-ray brightness in the wavelength range 1 to 8 Angstroms. The amount of energy released is the equivalent of millions of 100-megaton hydrogen bombs exploding at the same time! The first solar flare recorded in astronomical literature was on September 1, 1859. Two scientists, Richard C. Carrington and Richard Hodgson, were independently observing sunspots at the time, when they viewed a large flare in white light.
There are 3 categories: X-class flares are big; they are major events that can trigger planet-wide radio blackouts and long-lasting radiation storms. M-class flares are medium-sized; they can cause brief radio blackouts that affect Earth's polar regions. Minor radiation storms sometimes follow an M-class flare. Compared to X- and M-class events, C-class flares are small with few noticeable consequences here on Earth. The sun has sent out a powerful giant solar flare on July 2 and is expected to sweep past Earth’s magnetic field on Wednesday, July 4. The start of a solar explosion on the Sun’s surface was for the first time viewed by the scientists at the Inter-University Centre for Astronomy and Astrophysics (IUCAA), in collaboration with University of Cambridge and Rice University, USA. A sun storm was noticed rising from a large sunspot called AR1515 that is now facing the Earth side of the sun. It released an extremely forceful solar flare at 6:43 a.m. EDT (1043 GMT) on July 2. The flare registered as a class M5.6 solar storm on the scale used by astronomers to measure the sun’s weather.
Astronomer Tony Phillips said the solar flare released a wave of charged plasma called a coronal mass ejection (CME), but the particles were not aimed directly at Earth.
According to Spaceweather.com Tony Phillips stated, “The eruption also hurled a CME into space, but not directly toward Earth. The south-traveling cloud could deliver a glancing blow to our planet’s magnetosphere on July 4th or 5th.”
The strength of the solar flare is classified by three primary classes – C-class flares, M-class flares and X-class flares. The weakest storms are the C-class flares, which cause little effect that can be felt on Earth. M-class flares are moderate solar storms that can supercharge the Earth’s northern lights display.
The most powerful X-class solar flares can threaten spacecraft and astronauts in orbit; affect satellite signals, as well as harm power lines and other infrastructure on the ground, when targeted towards earth.
Scientist Durgesh Tripathi said hot gases evolved during large solar explosions would travel towards the earth which could affect power grids and satellites.
Helen Mason of the University of Cambridge said active regions are now arising frequently across the Sun. The opportunity to study them is facilitated with solar spacecraft, such as Hinode and the Solar Dynamics Observatory.
The study about solar flares would help in forecasting such explosions and in taking needed precautions to avoid damage to power grids and satellites.
RFERENCES:
- Truthdrive ; http://truthdive.com/2012/07/04/solar-flare-2012-sun-storm-could-reach-earth-by-july-4.html
- Spaceweather.com ; http://www.spaceweather.com/
