Corona
ENGLISH
A corona is a type of plasma "atmosphere" of the Sun or other celestial body, extending millions of kilometers into space, most easily seen during a total solar eclipse, but also observable in a coronagraph. The Latin root of the word corona means crown.
The sun's corona is much hotter (by a factor of nearly 200) than the visible surface of the Sun: the photosphere's average temperature is 5800 kelvin compared to the corona's one to three million kelvin. The corona is 10−12 times as dense as the photosphere, however, and so produces about one-millionth as much visible light. The corona is separated from the photosphere by the relatively shallow chromosphere. The exact mechanism by which the corona is heated is still the subject of some debate, but likely possibilities include induction by the Sun's magnetic field and sonic pressure waves from below (the latter being less probable now that coronae are known to be present in early-type, highly magnetic stars). The outer edges of the Sun's corona are constantly being transported away due to open magnetic flux generating the solar wind.
The Corona is not always evenly distributed across the surface of the sun. During periods of quiet, the corona is more or less confined to the equatorial regions, with coronal holes covering the polar regions. However during the Sun's active periods, the corona is evenly distributed over the equatorial and polar regions, though it is most prominent in areas with sunspot activity. The solar cycle spans approximately 11 years, from solar minimum to solar maximum, where the solar magnetic field is continually wound up (due to a differential rotation at the solar equator; the equator rotates quicker than the poles). Sunspot activity will be more pronounced at solar maximum where the magnetic field is twisted to a maximum. Associated with sunspots are coronal loops, loops of magnetic flux, upwelling from the solar interior. The magnetic flux pushes the hotter photosphere aside, exposing the cooler plasma below, thus creating the dark (when compared to the solar disk) spots.
More info: en.wikipedia.org/wiki/Corona
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CASTELLANO
La corona solar es la parte más exterior de la cromosfera, mide más un millón de kilómetros y puede observarse durante los eclipses solares o utilizando un dispositivo capaz de ocultar la luz del Sol y denominado coronógrafo. La densidad de la corona solar es un billón de veces inferior a la de la atmósfera terrestre y su temperatura alcanza los dos millones de grados (mientras que la fotosfera tiene una temperatura aproximada de 6000ºC).
La corona solar está compuesta por pequeñas partículas que son lanzadas al espacio por el intenso campo magnético solar produciendo el viento solar y, en fenómenos de eyección intensos, se puede producir una tormenta geomagnética en la Tierra. Estos átomos lanzados, al chocar con la parte superior de nuestra atmósfera son los causantes de las auroras en las regiones polares Norte y Sur.
Todos los detalles estructurales de la corona son debidas al campo magnético del Sol.
Más info: es.wikipedia.org/wiki/Corona_solar
Corona
ENGLISH
A corona is a type of plasma "atmosphere" of the Sun or other celestial body, extending millions of kilometers into space, most easily seen during a total solar eclipse, but also observable in a coronagraph. The Latin root of the word corona means crown.
The sun's corona is much hotter (by a factor of nearly 200) than the visible surface of the Sun: the photosphere's average temperature is 5800 kelvin compared to the corona's one to three million kelvin. The corona is 10−12 times as dense as the photosphere, however, and so produces about one-millionth as much visible light. The corona is separated from the photosphere by the relatively shallow chromosphere. The exact mechanism by which the corona is heated is still the subject of some debate, but likely possibilities include induction by the Sun's magnetic field and sonic pressure waves from below (the latter being less probable now that coronae are known to be present in early-type, highly magnetic stars). The outer edges of the Sun's corona are constantly being transported away due to open magnetic flux generating the solar wind.
The Corona is not always evenly distributed across the surface of the sun. During periods of quiet, the corona is more or less confined to the equatorial regions, with coronal holes covering the polar regions. However during the Sun's active periods, the corona is evenly distributed over the equatorial and polar regions, though it is most prominent in areas with sunspot activity. The solar cycle spans approximately 11 years, from solar minimum to solar maximum, where the solar magnetic field is continually wound up (due to a differential rotation at the solar equator; the equator rotates quicker than the poles). Sunspot activity will be more pronounced at solar maximum where the magnetic field is twisted to a maximum. Associated with sunspots are coronal loops, loops of magnetic flux, upwelling from the solar interior. The magnetic flux pushes the hotter photosphere aside, exposing the cooler plasma below, thus creating the dark (when compared to the solar disk) spots.
More info: en.wikipedia.org/wiki/Corona
--------------------------------
CASTELLANO
La corona solar es la parte más exterior de la cromosfera, mide más un millón de kilómetros y puede observarse durante los eclipses solares o utilizando un dispositivo capaz de ocultar la luz del Sol y denominado coronógrafo. La densidad de la corona solar es un billón de veces inferior a la de la atmósfera terrestre y su temperatura alcanza los dos millones de grados (mientras que la fotosfera tiene una temperatura aproximada de 6000ºC).
La corona solar está compuesta por pequeñas partículas que son lanzadas al espacio por el intenso campo magnético solar produciendo el viento solar y, en fenómenos de eyección intensos, se puede producir una tormenta geomagnética en la Tierra. Estos átomos lanzados, al chocar con la parte superior de nuestra atmósfera son los causantes de las auroras en las regiones polares Norte y Sur.
Todos los detalles estructurales de la corona son debidas al campo magnético del Sol.
Más info: es.wikipedia.org/wiki/Corona_solar