Why Coronal Loops ?


Sun spots are locations where the magnetic field is concentrated. The spots also normally occur is in pairs. These pairs represent the negative and positive regions of the magnetic field. Between the positive and negative areas there are magnetic field lines. Plasma gets trapped and is forced to travel along these field lines. This occurrence is called a coronal loop. The magnetic field can also store energy. When the field gets twisted and tangled enough it finally can take no more and releases its energy. This is a Coronal Mass Ejection (CME). Some of this energy gets 'hooked' by the suns gravity and reeled back into its atmosphere. The rest is thrown out into space with its own magnetic field. The earth experiences a constant solar wind, but if a CME is directed towards earth it is like a sudden huge gust of wind. The earths magnetosphere acts as a blanket or shield, repelling some of the gust, but some of the particles from the CME get trapped by the earth's magnetic field and creates Auroras from the particles inter acting with the atmosphere. Sometimes the result is not quite so pretty there are dangerous and destructive results from CME s. Astronauts, satellites, power grids ,and communications can be harmed or destroyed. So we can see that by studying coronal loops we can get more insight for forecasting the suns weather and improve the safety of our astronauts, satellites, and communications.




coronal loops image









in short:

1. Magnetic field lines fill the corona

2. Coronal loops can be observed when plasma is heated within a magnetic flux tube, resulting in
    ionization


3. The wavelength of the photons observed can be used to determine the ion formed in the loop, each
     ion being formed within a temperature range.

4. The values of temperature so determined are currently the most accurate temperature diagnostic  
    tool available to the observer. 



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