Solar+Flares

 SOLAR FLARES  

   solar flare is a thunderous explosion that occurs in the solar corona and chromosphere within the atmosphere of the Sun. The incredible energy level of a solar flare is equivalent to tens of millions of atomic bombs exploding at the same time!   Solar flares were first known to be occurring in 1859. Solar flare activity can vary from several per day to only a few a month, depending mostly upon the overall activity of the Sun as a whole. Solar activity generally varies on an 11-year cycle. At the peak of this “solar cycle” there are typically more sunspots on the surface of the Sun, which ultimately leads to more frequently occurring solar flares.   Solar flares are typically classified as A, B, C, M or X, depending upon the degree of their peak flux. Most solar flares occur in or around sun spots as the result of intense magnetic fields emerging from the Sun’s surface into the corona. The powerful energy commonly associated with solar flares can take as long as several days to build up, but only minutes to release.   During the occurrence of a solar flare, plasma is heated to tens of millions degrees Kelvin. Solar flares cannot typically be detected by the naked eye from the surface of the earth.  <span style="color: #aaaaaa; font-family: Arial,sans-serif;"> <span style="color: black; font-family: Arial,sans-serif;">

<span style="background-attachment: initial; background-clip: initial; background-color: red; background-image: initial; background-origin: initial; background-position: initial initial; background-repeat: initial initial; color: yellow; font-family: 'Century Gothic',sans-serif; font-size: 11pt;">What is a Solar Flare? <span style="color: #aaaaaa; font-family: Arial,sans-serif;"> <span style="color: black; font-family: Arial,sans-serif;"> <span style="background-attachment: initial; background-clip: initial; background-color: red; background-image: initial; background-origin: initial; background-position: initial initial; background-repeat: initial initial; color: yellow; font-family: 'Century Gothic',sans-serif; font-size: 11pt;">A flare is defined as a sudden, rapid, and intense variation in brightness. A solar flare occurs when magnetic energy that has built up in the solar atmosphere is suddenly released. Radiation is emitted across virtually the entire electromagnetic spectrum, from radio waves at the long wavelength end, through opticalemission to x-rays and gamma rays at the short wavelength end. <span style="color: #aaaaaa; font-family: Arial,sans-serif;"> <span style="color: black; font-family: Arial,sans-serif;"> <span style="background-attachment: initial; background-clip: initial; background-color: red; background-image: initial; background-origin: initial; background-position: initial initial; background-repeat: initial initial; color: yellow; font-family: 'Century Gothic',sans-serif; font-size: 11pt;">There are typically three stages to a solar flare. First is the precursor stage, where the release of magnetic energy is triggered. Soft x-ray emission is detected in this stage. In the second or impulsive stage, protons and electrons are accelerated to energies exceeding 1 Million electron volts. During the impulsive stage, radio waves, hard x-rays, and gamma rays are emitted. The gradual build up and decay of soft x-rays can be detected in the third, decay stage. The duration of these stages can be as short as a few seconds or as long as an hour. <span style="color: #aaaaaa; font-family: Arial,sans-serif;"> <span style="color: black; font-family: Arial,sans-serif;"> <span style="background-attachment: initial; background-clip: initial; background-color: red; background-image: initial; background-origin: initial; background-position: initial initial; background-repeat: initial initial; color: yellow; font-family: 'Century Gothic',sans-serif; font-size: 11pt;">Solar flares extend out to the layer of the Sun called the corona. The corona is the outermost atmosphere of the Sun, consisting of highly rarefied gas. This gas normally has a temperature of a few million degrees Kelvin. Inside a flare, the temperature typically reaches 10 or 20 million degrees Kelvin, and can be as high as 100 million degrees Kelvin. The corona is visible in soft x-rays, as in the above image. <span style="color: #aaaaaa; font-family: Arial,sans-serif;"> <span style="color: black; font-family: Arial,sans-serif;"> <span style="background-attachment: initial; background-clip: initial; background-color: red; background-image: initial; background-origin: initial; background-position: initial initial; background-repeat: initial initial; color: yellow; font-family: 'Century Gothic',sans-serif; font-size: 11pt;">The frequency of flares coincides with the Sun's eleven year cycle. When the solar cycle is at a minimum, active regions are small and rare and few solar flares are detected. These increase in number as the Sun approaches the maximum part of its cycle. The Sun will reach its next maximum in the year 2011, give or take one year. <span style="color: #aaaaaa; font-family: Arial,sans-serif;"> <span style="color: black; font-family: Arial,sans-serif;"> <span style="background-attachment: initial; background-clip: initial; background-color: red; background-image: initial; background-origin: initial; background-position: initial initial; background-repeat: initial initial; color: yellow; font-family: 'Century Gothic',sans-serif; font-size: 11pt;">A person cannot view a solar flare by simply staring at the Sun. (NEVER LOOK DIRECTLY AT THE SUN! EYE DAMAGE CAN RESULT.) Flares are in fact difficult to see against the bright emission from the photosphere. Instead, specialized scientific instruments are used to detect the radiation signatures emitted during a flare. The radio and optical emissions from flares can be observed with telescopes on the Earth. Energetic emissions such as x-rays and gamma rays require telescopes located in space, since these emissions do not penetrate the Earth's atmosphere. <span style="color: #aaaaaa; font-family: Arial,sans-serif;"> <span style="color: #aaaaaa; font-family: Arial,sans-serif;"> <span style="color: black; font-family: Arial,sans-serif;">