The sun is simple. Part Three: About Solar Flares
In the third part of my story we will focus on solar flares. I will tell about how they are formed and in general what it is.
As an example of the image we receive, I would like to give an image of the Sun obtained from the TRACE telescope. The white square indicates the approximate size of the Earth.
The previous parts are here and here .
So what is a solar flare? Solar flare is a process of powerful energy release near the surface of the sun. This grandiose phenomenon of nature is accompanied by the ejection of large streams of charged particles of various energies and powerful wave processes. The outbreak manifests itself in all ranges of the electromagnetic spectrum - from gamma radiation to kilometer long radio waves. In X-ray and radio beams, the brilliance and radiation flux from a flash can exceed the brightness and radiation flux from the entire Sun by many orders of magnitude.
During periods of maximum 11-year solar cycle, flares occur almost daily. However, weak flashes are most often observed. Outbreaks of average power, from which one can expect noticeable effects near the Earth, are quite rare — about one per week. During periods of minimum 11-year cycle for a few months, you can not register a single flash.
An outbreak is a very complex phenomenon and quite often consists of a large number of short-term (t <1c) energy releases in areas with significantly smaller sizes (d <1 thousand km). As a rule, powerful flares occur in magnetic fields of complex configuration, formed from a combination of coronal magnetic loops, the bases of which are sunspots or pores. The concentration of ions and electrons inside the flare loops varies from 109 to 1012 cm-3. The magnitude of the magnetic field in the flare coronal loops is usually from 50 to 700 Gs. The temperature of hot flash plasma reaches (2-5) * 107K.
Bright areas - active regions (AO) with a greatly increased magnetic field
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Image from the satellite SOHO, the sun is closed by a hood
How does the flash develop? As an example, I want to show one entertaining video of an equally entertaining flash. occurred on the sun on August 22, 2005. The video is derived from static images with an interval of 0.1s.
It is seen that the grounds first begin to glow, and then the main “glow” passes to the top and then dies away. This happens due to the fact that active radiating electrons from the depths of the Sun enter the flare loop, then move to the top and then, losing energy, fall out of the loop. I will explain schematically :)
The particle moves in a spiral, reflecting from the ends of the loop. If the angle is insufficient, then the particle falls out of the resulting magnetic trap (color line in the diagram). As a result, most of the active electrons accumulate with time at the top of the loop and from there it pours back into the Sun.
As always, a small wiki:
1. Magnetic trap - a magnetic field configuration capable of holding charged particles within itself.
2. Active regions are regions with a high magnetic field, and flashes are generated in them.
What to read on the topic:
1. V.F. Melnikov "Mysteries of Sunny Weather"
2. S.A. Kaplan "Entertaining radio astronomy"
PS It turned out to be a rather small article, in the next one I will try to tell about our observations and what we actually did on the example of one of the flashes. Also touch the software we used
UPD.
As an example of the image we receive, I would like to give an image of the Sun obtained from the TRACE telescope. The white square indicates the approximate size of the Earth.
The previous parts are here and here .
So what is a solar flare? Solar flare is a process of powerful energy release near the surface of the sun. This grandiose phenomenon of nature is accompanied by the ejection of large streams of charged particles of various energies and powerful wave processes. The outbreak manifests itself in all ranges of the electromagnetic spectrum - from gamma radiation to kilometer long radio waves. In X-ray and radio beams, the brilliance and radiation flux from a flash can exceed the brightness and radiation flux from the entire Sun by many orders of magnitude.
During periods of maximum 11-year solar cycle, flares occur almost daily. However, weak flashes are most often observed. Outbreaks of average power, from which one can expect noticeable effects near the Earth, are quite rare — about one per week. During periods of minimum 11-year cycle for a few months, you can not register a single flash.
An outbreak is a very complex phenomenon and quite often consists of a large number of short-term (t <1c) energy releases in areas with significantly smaller sizes (d <1 thousand km). As a rule, powerful flares occur in magnetic fields of complex configuration, formed from a combination of coronal magnetic loops, the bases of which are sunspots or pores. The concentration of ions and electrons inside the flare loops varies from 109 to 1012 cm-3. The magnitude of the magnetic field in the flare coronal loops is usually from 50 to 700 Gs. The temperature of hot flash plasma reaches (2-5) * 107K.
Bright areas - active regions (AO) with a greatly increased magnetic field
')
Image from the satellite SOHO, the sun is closed by a hood
How does the flash develop? As an example, I want to show one entertaining video of an equally entertaining flash. occurred on the sun on August 22, 2005. The video is derived from static images with an interval of 0.1s.
It is seen that the grounds first begin to glow, and then the main “glow” passes to the top and then dies away. This happens due to the fact that active radiating electrons from the depths of the Sun enter the flare loop, then move to the top and then, losing energy, fall out of the loop. I will explain schematically :)
The particle moves in a spiral, reflecting from the ends of the loop. If the angle is insufficient, then the particle falls out of the resulting magnetic trap (color line in the diagram). As a result, most of the active electrons accumulate with time at the top of the loop and from there it pours back into the Sun.
As always, a small wiki:
1. Magnetic trap - a magnetic field configuration capable of holding charged particles within itself.
2. Active regions are regions with a high magnetic field, and flashes are generated in them.
What to read on the topic:
1. V.F. Melnikov "Mysteries of Sunny Weather"
2. S.A. Kaplan "Entertaining radio astronomy"
PS It turned out to be a rather small article, in the next one I will try to tell about our observations and what we actually did on the example of one of the flashes. Also touch the software we used
UPD.
Source: https://habr.com/ru/post/84833/
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