Related topics: sun

Artificial intelligence helps improve NASA's eyes on the Sun

A group of researchers is using artificial intelligence techniques to calibrate some of NASA's images of the Sun, helping improve the data that scientists use for solar research. The new technique was published in the journal ...

Significant solar flare erupts from sun

The sun emitted a significant solar flare peaking at 10:29 a.m. EDT on July 3, 2021. NASA's Solar Dynamics Observatory, which watches the sun constantly, captured an image of the event.

Latest observations by MUSER help clarify solar eruptions

Prof. Yan Yihua and his research team from the National Astronomical Observatories of the Chinese Academy of Sciences (NAOC) recently released detailed results of observations by the new generation solar radio telescope—Mingantu ...

'Campfires' offer clue to solar heating mystery

Computer simulations show that the miniature solar flares nicknamed 'campfires," discovered last year by ESA's Solar Orbiter, are likely driven by a process that may contribute significantly to the heating of the sun's outer ...

The effects of solar flares on Earth's magnetosphere

Planet Earth is surrounded by a system of magnetic fields known as the magnetosphere. This vast, comet-shaped system deflects charged particles coming from the sun, shielding our planet from harmful particle radiation and ...

How do we know if an asteroid headed our way is dangerous?

There are a lot of things that pose a threat to our planet—climate change, natural disasters, and solar flares, for example. But one threat in particular often captures public imagination, finding itself popularised in ...

page 1 from 40

Solar flare

A solar flare is a big explosion in the Sun's atmosphere that can release as much as 6 × 1025 joules of energy. The term is also used to refer to similar phenomena in other stars, where the more accurate term stellar flare applies.

Solar flares affect all layers of the solar atmosphere (photosphere, corona, and chromosphere), heating plasma to tens of millions of kelvins and accelerating electrons, protons, and heavier ions to near the speed of light. They produce radiation across the electromagnetic spectrum at all wavelengths, from radio waves to gamma rays. Most flares occur in active regions around sunspots, where intense magnetic fields penetrate the photosphere to link the corona to the solar interior. Flares are powered by the sudden (timescales of minutes to tens of minutes) release of magnetic energy stored in the corona. If a solar flare is exceptionally powerful, it can cause coronal mass ejections.

X-rays and UV radiation emitted by solar flares can affect Earth's ionosphere and disrupt long-range radio communications. Direct radio emission at decimetric wavelengths may disturb operation of radars and other devices operating at these frequencies.

Solar flares were first observed on the Sun by Richard Christopher Carrington and independently by Richard Hodgson in 1859 as localized visible brightenings of small areas within a sunspot group. Stellar flares have also been observed on a variety of other stars.

The frequency of occurrence of solar flares varies, from several per day when the Sun is particularly "active" to less than one each week when the Sun is "quiet". Large flares are less frequent than smaller ones. Solar activity varies with an 11-year cycle (the solar cycle). At the peak of the cycle there are typically more sunspots on the Sun, and hence more solar flares.

This text uses material from Wikipedia, licensed under CC BY-SA