O que é uma Solar-Flare?
Antonio Matias
What is a Solar Flare?
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. The amount of energy released is the equivalent of millions of 100-megaton hydrogen bombs exploding at the same time! The first solar flare recorded in astronomical literature was on September 1, 1859. Two scientists, Richard C. Carrington and Richard Hodgson, were independently observing sunspots at the time, when they viewed a large flare in white light.
Soft x-ray image of a solar flare on the Sun
As the magnetic energy is being released, particles, including electrons, protons, and heavy nuclei, are heated and accelerated in the solar atmosphere. The energy released during a flare is typically on the order of 1027 ergs per second. Large flares can emit up to 1032 ergs of energy. This energy is ten million times greater than the energy released from a volcanic explosion. On the other hand, it is less than one-tenth of the total energy emitted by the Sun every second.
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 MeV. 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.
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. Notice that the corona is not uniformly bright, but is concentrated around the solar equator in loop-shaped features. These bright loops are located within and connect areas of strong magnetic field called active regions. Sunspots are located within these active regions. Solar flares occur in active regions.
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.
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.
--
António Matias
Antonio Matias
The Classification of X-ray Solar Flares A solar flare is an explosion on the Sun that happens when energy stored in twisted magnetic fields (usually above sunspots) is suddenly released. Flares produce a burst of radiation across the electromagnetic spectrum, from radio waves to x-rays and gamma-rays. [more information] Scientists classify solar flares according to their x-ray brightness in the wavelength range 1 to 8 Angstroms. There are 3 categories: X-class flares are big; they are major events that can trigger planet-wide radio blackouts and long-lasting radiation storms. M-class flares are medium-sized; they can cause brief radio blackouts that affect Earth's polar regions. Minor radiation storms sometimes follow an M-class flare. Compared to X- and M-class events, C-class flares are small with few noticeable consequences here on Earth. This figure shows a series of solar flares detected by NOAA satellites in July 2000:  Each category for x-ray flares has nine subdivisions ranging from, e.g., C1 to C9, M1 to M9, and X1 to X9. In this figure, the three indicated flares registered (from left to right) X2, M5, and X6. The X6 flare triggered a radiation storm around Earth nicknamed the Bastille Day event.
|
Luis Cupido
< O que � uma fulgura��o solar ? >
Bem sei que poucos usam falar em Portugu�s nestas coisas...
Mas emfim, aqui fica a tradu��o para quem gostar mais...
Subsiste, claro est�, a d�vida se � melhor falar Portugu�s ou
usar Ingl�s para t�r a certeza que todos entendem...
...isso � que eu j� n�o sei :-(
lc.
ct1dmk.
P.S. Ant�nio, estou a ver que est�s entusiasmado com o
in�cio o ciclo solar que vem a� ;-) :-)
Antonio Matias wrote:
> Ainda, sobre Solar-Flares, como classifica-las
>
>
>
>
>
> The Classification of X-ray Solar Flares
> or "Solar Flare Alphabet Soup"
>
> A solar flare is an explosion on the Sun that happens when energy stored
> in twisted magnetic fields (usually above sunspots) is suddenly
> released. Flares produce a burst of radiation across the electromagnetic
> spectrum, from radio waves to x-rays and gamma-rays. [more information
> <http://hesperia.gsfc.nasa.gov/sftheory/flare.htm>]
>
> Scientists classify solar flares according to their x-ray brightness in
> the wavelength range 1 to 8 Angstroms. There are 3 categories: *X-class
> flares* are big; they are major events that can trigger planet-wide
> radio blackouts and long-lasting radiation storms. *M-class flares* are
> medium-sized; they can cause brief radio blackouts that affect Earth's
> polar regions. Minor radiation storms sometimes follow an M-class flare.
> Compared to X- and M-class events, *C-class flares* are small with few
> noticeable consequences here on Earth.
>
> This figure shows a series of solar flares detected by NOAA satellites
> in July 2000:
>
>
>
> Each category for x-ray flares has nine subdivisions ranging
> from, /e.g./, C1 to C9, M1 to M9, and X1 to X9. In this figure, the
> three indicated flares registered (from left to right) X2, M5, and X6.
> The X6 flare triggered a radiation storm around Earth nicknamed
> the Bastille Day event
> <http://science.nasa.gov/headlines/y2000/ast14jul_2m.htm>.
>
> /Class/
>
> /Peak (W/m//^2 )between 1 and 8 Angstroms/
>
> *B*
>
> I < 10^-6
>
> *C*
>
> 10^-6 < = I < 10^-5
>
> *M*
>
> 10^-5 < = I < 10^-4
>
> *X*
>
> I > = 10^-4
>
>
> No dia 10 de Mar�o de 2011 12:21, Antonio Matias <ct1...@gmail.com
> <mailto:ct1...@gmail.com>> escreveu:
>
>
> What is a Solar Flare?
>
> *A flare is defined as a sudden, rapid, and intense variation in
> brightness. A **solar flare*
> <http://hesperia.gsfc.nasa.gov/sftheory/glossary.htm#FLARE>* occurs
> when magnetic energy that has built up in the **solar atmosphere*
> <http://hesperia.gsfc.nasa.gov/sftheory/glossary.htm#SOLAR_ATMOSPHERE>* is
> suddenly released. **Radiation*
> <http://hesperia.gsfc.nasa.gov/sftheory/glossary.htm#ELECTROMAGNETIC_RADIATION>* is
> emitted across virtually the entire **electromagnetic spectrum*
> <http://hesperia.gsfc.nasa.gov/sftheory/glossary.htm#ELECTROMAGNETIC_SPECTRUM>*,
> from radio waves at the long **wavelength*
> <http://hesperia.gsfc.nasa.gov/sftheory/glossary.htm#WAVELENGTH>* end,
> through **optical*
> <http://hesperia.gsfc.nasa.gov/sftheory/glossary.htm#OPTICAL>*emission
> to **x-rays*
> <http://hesperia.gsfc.nasa.gov/sftheory/glossary.htm#X_RAY>* and **gamma
> rays*
> <http://hesperia.gsfc.nasa.gov/sftheory/glossary.htm#GAMMA_RAY>* at
> the short wavelength end. The amount of energy released is the
> equivalent of millions of 100-**megaton*
> <http://hesperia.gsfc.nasa.gov/sftheory/glossary.htm#MEGATON>* hydrogen
> bombs exploding at the same time! The first solar flare recorded in
> astronomical literature was on September 1, 1859. Two scientists,
> Richard C. Carrington and Richard Hodgson, were independently
> observing **sunspots*
> <http://hesperia.gsfc.nasa.gov/sftheory/glossary.htm#SUNSPOT>* at
> the time, when they viewed a large flare in **white light*
> <http://hesperia.gsfc.nasa.gov/sftheory/glossary.htm#WHITE_LIGHT>*.*
>
>
> Full Disk Corona with Flare Soft x-ray image of a solar
> flare on the Sun
> <http://hesperia.gsfc.nasa.gov/sftheory/fulldisk.htm>
>
> *As the magnetic energy is being released, particles,
> including **electrons*
> <http://hesperia.gsfc.nasa.gov/sftheory/glossary.htm#ELECTRON>*, **protons*
> <http://hesperia.gsfc.nasa.gov/sftheory/glossary.htm#PROTON>*, and
> heavy **nuclei*
> <http://hesperia.gsfc.nasa.gov/sftheory/glossary.htm#NUCLEUS>*, are
> heated and accelerated in the solar atmosphere. The energy released
> during a flare is typically on the order of 10*^*27* * **ergs*
> <http://hesperia.gsfc.nasa.gov/sftheory/glossary.htm#ERGS>* per
> second. Large flares can emit up to 10*^*32* * ergs of energy. This
> energy is ten million times greater than the energy released from a
> volcanic explosion. On the other hand, it is less than one-tenth of
> the total energy emitted by the Sun every second.*
>
> *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 **MeV*
> <http://hesperia.gsfc.nasa.gov/sftheory/glossary.htm#MEV>*. 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.*
>
> *Solar flares extend out to the layer of the Sun called
> the **corona*
> <http://hesperia.gsfc.nasa.gov/sftheory/glossary.htm#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*
> <http://hesperia.gsfc.nasa.gov/sftheory/glossary.htm#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. Notice
> that the corona is not uniformly bright, but is concentrated around
> the solar equator in loop-shaped features. These bright loops are
> located within and connect areas of strong **magnetic field*
> <http://hesperia.gsfc.nasa.gov/sftheory/glossary.htm#MAGNETIC_FIELD>* called */*active
> regions*/*. Sunspots are located within these active regions. Solar
> flares occur in active regions.*
>
> *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.*
>
> *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*
> <http://hesperia.gsfc.nasa.gov/sftheory/glossary.htm#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.*
>
>
>
>
> --
> Ant�nio Matias
>
> CT1FFU - CR5A
>
> www.dxpatrol.com <http://www.dxpatrol.com>
>
> QRV: HF, 6m, 4m,2m,70cm,23cm
> SSB, CW, MGM
> DX, EME, Contest,Sat.
>
>
>
>
>
> --
> Ant�nio Matias
>
> CT1FFU - CR5A
>
> www.dxpatrol.com <http://www.dxpatrol.com>
Antonio Matias
flare = fulguração.
< O que é uma fulguração solar ? >
Bem sei que poucos usam falar em Português nestas coisas...
Mas emfim, aqui fica a tradução para quem gostar mais...
Subsiste, claro está, a dúvida se é melhor falar Português ou
usar Inglês para têr a certeza que todos entendem...
...isso é que eu já não sei :-(
lc.
ct1dmk.
P.S. António, estou a ver que estás entusiasmado com o
início o ciclo solar que vem aí ;-) :-)
Antonio Matias wrote:
-- António Matiaswww.dxpatrol.com <http://www.dxpatrol.com>
CT1FFU - CR5A
QRV: HF, 6m, 4m,2m,70cm,23cm
SSB, CW, MGM
DX, EME, Contest,Sat.
--
António Matias
CT1FFU - CR5A
www.dxpatrol.com <http://www.dxpatrol.com>QRV: HF, 6m, 4m,2m,70cm,23cm
SSB, CW, MGM
DX, EME, Contest,Sat.
Luis Cupido
> mas obviamente n�o soavam nada bem.
Cientificamente, fulgura��o � usado pelo pessoal dos plasmas solares
como tal acho que podemos com confian�a usar o termo.
> Muito obrigado pela correc��o.
Pois, mas n�o foi de todo uma correc��o, mas sim
uma nota para todos, dando t�o somente a alternativa.
� que na realidade eu respeito completamente
quem prefere usar certos termos t�cnicos em ligua Inglesa
eu pessoalmente uso muitos, acho que n�o se consegue evitar
em muitos casos... portanto foi mesmo s� uma informa��o...
73's
Luis Cupido
ct1dmk.
Antonio Matias wrote:
> Ora viva.
> Boa tarde.
> Efectivamente, tamb�m gosto de usar termos em Portugu�s.
> Usei o termo Flare, porque simplesmente desconhecia o termo correcto a
> dar em Portugu�s.
> J� tinha pensado em: Chama, Labareda, L�ngua-de-fogo etc,
> mas obviamente n�o soavam nada bem.
> Agora j� sei.
> Fulgura��o, ser� o termo a partir de agora :-)
>
> Quanto ao ciclo24, sim estou entusiasmado, vai ser o meu segundo e meio
> ciclo como radio-amador, mas o primeiro
> onde acompanho mais pormenorizadamente os efeitos.
> Quem gosta de estudar os mist�rios da propaga��o ionosf�rica vai ter
> muito que se entreter.
>
> Muito obrigado pela correc��o.
> Melhores 73
> Matias
>
>
> 2011/3/10 Luis Cupido <cup...@mail.ua.pt <mailto:cup...@mail.ua.pt>>
>
> flare = fulgura��o.
>
> < O que � uma fulgura��o solar ? >
>
> Bem sei que poucos usam falar em Portugu�s nestas coisas...
> Mas emfim, aqui fica a tradu��o para quem gostar mais...
>
> Subsiste, claro est�, a d�vida se � melhor falar Portugu�s ou
> usar Ingl�s para t�r a certeza que todos entendem...
> ...isso � que eu j� n�o sei :-(
>
> lc.
> ct1dmk.
>
> P.S. Ant�nio, estou a ver que est�s entusiasmado com o
> in�cio o ciclo solar que vem a� ;-) :-)
> No dia 10 de Mar�o de 2011 12:21, Antonio Matias
> <ct1...@gmail.com <mailto:ct1...@gmail.com>
> <mailto:ct1...@gmail.com <mailto:ct1...@gmail.com>>> escreveu:
> -- Ant�nio Matias
>
> CT1FFU - CR5A
> www.dxpatrol.com <http://www.dxpatrol.com>
> <http://www.dxpatrol.com>
> QRV: HF, 6m, 4m,2m,70cm,23cm
> SSB, CW, MGM
> DX, EME, Contest,Sat.
>
>
>
>
>
> --
> Ant�nio Matias
>
> CT1FFU - CR5A
> www.dxpatrol.com <http://www.dxpatrol.com>
> <http://www.dxpatrol.com>
> QRV: HF, 6m, 4m,2m,70cm,23cm
> SSB, CW, MGM
> DX, EME, Contest,Sat.
>
>
>
>
>
> --
> Ant�nio Matias
