Just a few October day we learned about exoplanets as much as never learned for all the previous months. Main news: now why to fly to the nearest star.

Tell me, what associations do you have the word "carbon"? Probably something black, packagesa. And it is natural: he's carbon. And the coal - is that what you have with different degree of commitment to wash. The image of the courageous, but aesthetically unattractive. So something cosmic, presumably rich in carbon, systematically presented as a diamond. A little over a year has passed since the last brilliant imagination, and once again the world is blinded by the glitter another diamond planet.

Hero of the day - planet Cancer 55 e. In this notation, the letter "a" is reserved for the star, and the following letters are indicated planet in order of their opening (not in order of removal from the stars, as you might think). In the system 55 Cancer five planets, and the letter "e" marked the one that is drawn closer to the star.

Planet Cancer 55 e was discovered in 2004, but we have to admit that none of its initially, certain parameters have not stood the test of time. One of the main discrepancies were not correctly specified period. Based on observations made with the help of telescope Hobby-Eberle (USA), Barbara McArthur (University of Texas, USA) and her colleagues have determined that the fluctuations of the radial velocity of the star, presumably caused by gravity close planet with a minimum mass of about 15 Earth masses, going on about 2.8 days. However, in 2010 Rebecca Dawson and Daniel Fabritski (astrophysics Harvard center, USA) suggested that this apparent periodicity arises from the fact that the data on radial velocities are fixed not continuously, and with a period of about a day (watch-it is possible only at night). Taking into account the periodicity of observations, Dawson and Fabrycky received for the period 55 Cancer e four times less - only about 0.7 days.

This clarification was confirmed in 2011, when it was revealed that the planet "e" is eclipsing, that is periodically, namely every 0.74 days passes in front of the stellar disk and slightly outshines it. Observations of eclipses is not something that the observations of the radial velocities. Thanks to them you get the opportunity to consider not only the mass of the planet (radial-velocity method gives only the lower border of the masses), but also its size. The mass of the planet was equal to 8.4 Land mass and diameter greater than earth is approximately two times.

Here the Nikko Madhusudhan (Yale University, USA) and his colleagues and was taken to the stage carbon. The size of a given mass of the planet depends on its chemical composition, the assumption is quite natural that the planet is in a state of hydrostatic equilibrium. Look at the first picture of their article: at a fixed mass of the minimum size will have an iron planet, and the maximum water. For "the earth" silicate composition planet Cancer 55 e is too large. This problem was tried to be solved by assuming that its rocky core surrounded by powerful water shell. For the planet, which flies to 2 million miles from its star (30 times closer to the star than mercury is to the Sun), this seems rather strange.

Madhusudhan with co-authors suggested a more natural solution. Itself the star 55 Cancer is significantly richer in carbon than the Sun. If the Sun carbon by the number of atoms almost twice as inferior to oxygen, 55 Cancer of carbon atoms slightly larger than atoms of oxygen. However, the authors warn, evaluation of the content of C and O star can be burdened by systematic errors. However, if you take them for granted, and assume that the composition of the protoplanetary substances was similar to the composition of the stars, we come to the conclusion that the planetary system 55 Cancer can also be rich in carbon. Rich to such an extent that carbon or its compounds form the basis of rocks on the planet "e".

Madhusudhan and his colleagues were mixed in different proportions iron core, mantle silicon carbide or MgSiO3 and carbon bark and looked what the size of the planet must be obtained. It turned out that depending on the weight of the iron core carbon fraction and (or) of silicon carbide in the composition of the earth varies from 10 to almost 100 percent. To dispense with carbon possible only on the assumption that the composition of the planet has no iron. This assumption is in and of itself looks weird, and the high content of iron in the parent star of the planet (in two times more than the Sun) makes it even more strange.

In General, most likely, the outer layers 55 Cancer E. really rich in carbon, but in what form? On this question, the model calculations definite answer can not give; the right of observation. Unfortunately, in the mass consciousness leadership role played by the word diamond"deliberately used by the authors in a press release. And described a press fantasies diamond planet! Several media called and asked, are there any prospects of gas production. Said, "she's just a forty light-years!" That's because as much diamonds want. Headers "Found graphite planet", podi, such agiotage would not be called. By the way, diamond planet and approximate methods of delivery of diamonds with her on the Ground described in 1950-ies - the story of Tom Godwin "necessity is the mother of invention".

Unfortunately, diamond smoke overshadowed the real importance of this work is another step to the study of chemistry and evolution "carbon" drive, which I wrote at the end of last "diamond column". Unnoticed passed and the possible detection of hydrogen atmosphere of another planet from the system 55 Cancer - planet "b".

As soon as we observe the Eclipse of a star by the planet "e", other planets also have to fly somewhere before star. Even if the planet itself and is not directly in front of the stellar disk, it can partially close it with its atmosphere. David Ehrenreich (Grenoble Institute of planetology and astrophysics, France) and his colleagues observed the star 55 Cancer during her eclipses planet "e" and alleged bottom connection with the planet "b".

In the first case, the spectrum of the star did not change. This means that the planet "e" anything significant gas envelope no, which is consistent with its new "carbon" models. But while the lower connection with the planet "b" in the spectrum of a star, there is a significant line of hydrogen absorption issuing the presence of powerful planet's atmosphere.

But the absolute hit of the past days is a planet of the star alpha Centauri B. Dreams of a planetary system of the nearest to us stars for many decades. Not to fly four light years it was much easier than to fly forty. But still it would be nice to know for direct studies of extrasolar planetary systems sufficient to cover the minimum distance. Therefore, the attempts to find the planet at Proxima, or the components of the binary alpha Centauri there have been several.

Hopes for a long time spoil it duality nearest to us a pair of sun-like stars. It was considered that in binary systems neither education nor sustainable existence of the planetary system is impossible. Discoveries of recent years (and again last days) show that the planets in multiple systems are not so exotic. Yes that far to go: 55 Cancer is also double. Therefore, expectations as to alpha Centauri continued unabated.

And then, finally, the success! Four years of painstaking observations on the 3.6-meter telescope of ESO using the best spectrograph showed that the less bright and less hot two components have planetary satellite. However, this is not quite what we had dreamed of. Body with a minimum mass of a little more than the Land mass of flies around a star just six million miles from it. If that "the earth", it is very hot. But the first step is the hardest: the discovery of extrasolar giant planets also started with "hot Jupiter".