By that time, however, it was already clear that the chemicals can not enter freely; they form a strict sequence, which reveals a number of regularities, families and groups. Where Place the crown? I thought about this and the great Russian scientist Dmitri Mendeleev, the next in 1869 offered the first version of the periodic table of chemical elements. Unable to find a better place for the crown, he put him in front of hydrogen, writing at the same time … As the years passed. In 1895, he was found on the Earth element, open Zhansenom Pierre and received thanks to its solar origin, the name of helium. While the crown all the same remained hypothetical element, traces of which could not be found either in the Earth’s atmosphere, or in minerals, and then he disappeared completely from physics. However, the green line 530.3 nm persistently continued to be present in all optical spectra produced in solar eclipses.
Finally, in the 1930s. This line has been detected again, but not on Earth, and not even in the sun and in deep space — in the spectrum of a new star, which had a temperature of the emitting gas of a few million degrees. Based on this fact, and astronomers spectroscopists Bengg Elden Swede and a German, Walter Grotrian proved that in the solar corona at a wavelength of 530.3 nm shines most ordinary iron, but because of high ambient temperatures up to a huge ionized -13 th degree, the have lost 12 of their 26 electrons.
One mystery was solved thereby, but in its place came another. The light coming to us from the sun, clearly radiating object with a surface temperature of about 5800 K. The solar corona is surrounding this «cold» solar sphere, as it turned out, red-hot to 2 million degrees. Thermodynamics tells us that heat can not be transferred from a cold to a hot body. Sun all kind shows the opposite. This is demonstrated and observed solar-type stars. They all have a huge cold surface and extending millions of kilometers, red-hot outer atmosphere, the so-called crown.
What energy is required to heat the corona and how fast it cools down at all? It is not difficult to calculate the thermal energy. It is known as electrons and protons contained in the crown (of, for example, can be very accurate «count» during a solar eclipse by measuring the brightness of the corona in the visible radiation). Known and thermal energy of each particle — it can be determined if the temperature of the corona, is 1-2 million K. Multiplying one by the other, we find that the heat in the crown of approximately 1026 J. This is of course a lot. For example, if we started to warm crown, using the full power of Russia’s largest power plant (which is about 1017 J per year), we have gone to a billion years. A lot of it for the sun, we’ll see below, but for now let’s ask ourselves: how to quickly cool down the crown? Sun in fact located in a space that is in a kind of giant thermos. So maybe his crown and do not have to heat all the time, she just can not cool off? And whatever it was created with a temperature of 4 billion years ago, and then you can think of. Unfortunately, this is not so. Crown and cools down very quickly. Cools it due to the fact, which is why she and visible — due to their radiation. It is easy to calculate that if the solar corona stop warming, it cools down, it has a fully disappear within 3-4 hours. It is so much time for her entire thermal energy appears in the form of radiation. So, we know that the energy of the corona is about 1026 joules of energy and cools it in 4 hours. Well, now we know how to pace it should be warm, and we can see what is able to provide such a pace.
Generally speaking, in 1026 George is a lot ‘for the Earth, but very little of the sun. This energy it emits just a second, and in the over the last several billion years. But, unfortunately, all this «cold» visible light. The energy of these photons is about 1 eV (which measures the units such as low value, and if you translate them into more familiar language, we get 1.6 * October 19 J). Even if these light photons are absorbed in the solar corona, heat it, they will only be able to several thousand degrees. I pack to be, no matter how tempting, but it is necessary to look for other sources of energy, which form the «hot» radiation and hot stuff. And these sources are — this solar flares. A solar flare — a solar blast, but it’s a strange explosion. On the sun no explosives, no sophisticated chemistry. Its main elements — a protons and electrons. What do they explode? They explode in the Sun, as strange as it sounds, electric currents. Every probably happened: we enter a dark room, turn on a light bulb, and suddenly cotton, and it will burn. Few people know that only he fully echoed only on the microscale, a solar flare. Replacement of the wire length of the gigantic currents in the tens of thousands of kilometers, the current in the solar atmosphere, the light bulb will replace a number of current area of the collision, and the magnetic switch on the trigger that starts the process of self-destruction of this configuration. Turn. Explosion. Fly away energetic particles accelerated to relativistic energies are thrown out into interplanetary space pieces of the solar atmosphere, some of which have even drifted to Earth, clouds swirling red-hot plasma with a temperature of more than 10 million degrees. Oh, and if it is impossible to heat the corona, what, then, can be! Nevertheless, even such power, as it turns out, is not enough. The fact that the crown of the Sun cools down too quickly. If you take a period of 1 year and divide it by the cooling time of the crown, 4 hours, it turns out that for the year the crown of the sun can cool down again in 2200. Solar flare well, though there is so much great energy that at one time can be completely heat the solar corona, still occur rarely. For example, for 12 months of 2012 the Sun was only seven outbreaks perfect score, denoted by the letter X (X). In other words, the crown of the Sun in the past year could be heated seven times larger outbreaks. If you take a smaller flash points (they are denoted by the letter M and the English for the heating of the corona need 10 pieces), they are in 2012, there were 130, and they can warm up even the crown 13 times. Take, finally, the weakest of the reliably observed solar flares, so-called Class C. They are for single coronal heating is necessary to have at least 100. There has them in 2012 1600 pieces, and heat the corona, they thus could still 16 times. Fold the resulting values - 7 + 13 + 16 And we see that all of the observed solar flare in 2012 could heat the crown 36 times. A cool solar corona 2200 times. As it was warm in the remaining 2164 cases? The attentive reader must have noticed that the more we took the weak flash, the higher is their overall effectiveness. And this is no accident. Indeed, the whole experience of watching the sun says that, despite the fact that the big, giant flare attracted worldwide attention, and their overall contribution to the solar activity is relatively low. The main energy is released is still not in them, but in a much more modest events that often go unnoticed, but the sum of its superior event-giants.
Then again, the reader may ask, can not exist if the Sun outbreak so weak that even the fact that they can not register with modern instruments, but the total energy of hundreds and thousands of times the energy of the big events? That reasoning so solar astronomers have come to the concept of «solar nanovspyshki.»
The term nanovspyshka very unusual. In this age of miniaturization we hear the word «nano» in various combinations «nanoworld», «nanoelectronics», «nanotechnology». However, what it means to «nano» when we are talking about such huge projects as the sun? Of course, by earthly standards, even in the sun nanosobytie an event of enormous proportions by the standards of the Earth. For comparison, a solar nanovspyshka gives the same amount of energy as the Earth receives from the Sun for one hundredth of a second. But by the standards of the Sun is a — an event-dwarf. The word «nano» in this context means that the energy released in these outbreaks is equal to one billionth of the energy of the largest flash. Or, in other words, events that are about a million times weaker than the flash of the lowest classes of confidence observed solar flares — Class C
There is one very important argument in favor of the fact that these events actually exist. Solar activity is not constant — it varies cyclically with a period of 11 years. This is the famous 11-year-old solar cycle, which runs from 1749 now in particular, we are living in an era of maximum solar cycle number 24. However, apart from highs in the cycle there and lows — the deep failures in solar activity, when For several months, and sometimes years, the Sun does not occur from solar flares. The most recent failure was at the junction of the 2008 — 2009. It is interesting in this context to look at the hot corona of the sun during a solar minimum. What was happening to her, she cools down, reducing its temperature, maybe even disappear? Observations show that, in terms of temperature, with crown nothing happens. Despite the complete lack of outbreaks and of any other visible manifestations of solar activity, it continues with something warm at the same rate as during the solar maximum. What is this if not evidence of hidden, invisible reservoir of energy?
The task see the invisible — and see the sun nanovspyshki — one of the most spectacular in the modern solar physics. Infiltrate a sunny microcosm is managed very small number of experiments, and perhaps more profoundly than anyone could look our Russian TESIS complex space telescopes, worked in 2009 on the CORONAS-Fotop.
2009 was a very unusual not only by the standards of recent years, but even in comparison with all the more than 250-year history of the observation of the solar cycle. Solar activity this year has dropped to one of the lowest levels in history. Such a situation, when the sun does not «big» the activity was obviously very favorable for observation and exploration of the world of weak solar events: micro- and nanovspyshek. Much more important for success, however, was not it, and the very high sensitivity of scientific instruments, which could for the first time in the world right to see the events with energies of about 10-100 times smaller than before.
What was able to see through the eyes of these telescopes?
First of all, failed to register in the lower corona of the sun set (tens of thousands every hour), small-scale radiation bursts, the sources of which have a size of no more than 1-2 pixels of the image (this is «only» 2-4 thousand. Km). The duration of a single burst was no more than 3-5 minutes, despite the fact that the duration of the «large» solar flares up to several hours. Since the device has a very high temporal resolution of about 4 compared to 30-60 at the same time working with foreign space telescopes, the time profiles of these bursts were registered with a unique detail, and, accordingly, was very accurately measured the energy is released in the event. It was around 1023-1025 erg, ie from 10 10 to 10’8 energy large solar flare, is up to 1033 erg. It is this energy that should be released in a hypothetical solar nanovspyshkah. It is enough, however, to the fact of the burst of radiation, to name the observed event nanovspyshkoy? No sufficient. The fact that the physics of the Sun called the flare energy release is not any, and it is only a certain nature — when solar energy is drawn from the explosion energy of the magnetic fields and electric currents. The main symptom of the outbreak — a change in the magnetic configuration of the area where it occurs. This change says that the region really gave part of their magnetic energy and had to be reconstructed in a configuration with a lower magnetic energy. It would, for events, the dimensions of which are at the limit of the spatial resolution of the instrument, to register changes in the spatial structure will generally be impossible. Nevertheless, at least one witness able to obtain reliable. In one of the detected solar nanovspyshek, dated 22 November 2009, changes the magnetic configuration proved to be so strong that they could be seen in the image. The two magnetic loops that have been divided before the outbreak, after it merged in an image into one magnetic configuration. This process of merging magnetic loops was ho- ‘well-known for his observations of large outbreaks, but also surprisingly turned out to see him and sunny micro-world and see that the same physical principles are repeated on a completely different scale of space.
See with your own eyes nanosobytiya in the solar corona — is truly inspiring result. However, how to check that they are able to play exactly the role they assign — able to heat the solar corona? For this we need to show at least two things. The first show that nanovspyshek not just a lot, but enough to outperform all other energy known types of outbreaks. And the second — to make sure that nanovspyshki not just exist, but really warm plasma around. Both problems, given that the observations were carried out at the limits of the tools look like a puzzle, but, nevertheless, they managed to solve.
Sun in the low activity
Ensure that nanovspyshek happens quite a lot, it managed fairly simple, but at the same time, elegant way. Suppose that we have every second in the Sun takes place a number of outbreaks 14 ,, each of which has an energy E. Then one second together they produce and, • E Energy. Now imagine that we have yet another class of weaker flares with the pace and, and energy is ten times less: 0.1 • E. The total energy in these weak flares will be equal to 0.1 * N3 • EV is easy to understand that if the rate of production weak flares, U2, at 10 times higher than the rate of large outbreaks of the M1, the total energy in the outbreaks of both classes will be the same. Unless lt; 10 * N5, the outbreak of large events dominate the weak and accounting nanovspy-cheek in the coronal heating problem makes no sense. Thus, it is necessary to make sure that H gt; 10 * N ,. In fact, it’s been done.
Finally, the last and perhaps the most interesting task was to register the hot plasma in weak solar events. Authentically found at the Sun high temperature plasma (several million degrees) is very difficult. The fact is that whatever device you have not seen our star, almost always in the bandwidth of your instrument with radiation from the hot plasma and the light will penetrate the «cold» spectral lines. So too is the dense solar spectrum. How to separate the radiation of hot plasma from the cold background? Here come to the aid of a very interesting technology — used to focus the image is not an ordinary mirror and a quartz crystal. Its grid is so small sizes that can reflect the X-rays, and if you make the grille and more spherical, it is not merely reflect, but also focus them better than the telescope mirror. The main thing is that this will be reflected only one spectral line with a wavelength which is consistent with the lattice constant. This condition is called Wulff — Bragg. So tough way and managed to get a picture of the sun in a single line — magnesium ion XII, the wavelength of 0.842 nm. This line is remarkable that shines only from the temperature of 4-5 million degrees. Cold plasma in these images simply do not. This device and showed that even in a deep minimum of solar activity in 2009, when for months in the sun there was no outbreaks in its crown periodically appears briefly very compact, but, of course, the hot springs of radiation at a temperature not lower than 4 million degrees. They managed to identify outbreaks of very low power — about 1026-1027 erg.
nProniknut even further at the time failed. Solar activity in the second half of 2009 began to grow, and the conditions for observing the Sun nanosobyty deteriorated. And in late 2009, he finished work and the satellite Coronas-Photon. But the next step, we believe, will be able to do very soon. In 2015, at the Earth’s orbit to be launched new generation solar telescope, which is being developed at the Physics Institute of the Russian Academy of Sciences (FIAN). This telescope will be able for the first time in the world to see on the solar surface details of about 75 km. For comparison telescopes on satellite Coronas-Photon seen shiny objects, starting with the size of 1000 km. And then, perhaps, sunny microcosm unfold before us in a new way, perhaps again turning our understanding of the sun.