Planet Cancer 55 e, "super-earths", located in a sun-like star HD 75732 (55 Cancer, spectral class G8V), was opened in 2004. This is one of the closest to the Earth "supertall": up to its planetary system just 40,9 light years. It is about 8.6 times heavier than Earth, and its diameter is twice bigger than ours. Thus, the density of the Earth and Cancer 55 e quite comparable.

Recent study conducted at Yale University (USA), puts forward the thesis that the "super-earths" is a typical carbon planet, class of exoplanets, which until only discussed as theoretically possible. "This is the first look at the rocky world, with chemistry, fundamentally different from earthly - emphasizes the lead author of the Nikko Madhusudhan. - The surface of the planet rather coated graphite and diamonds than water and granite."

But chemistry, categorically excellent called hot climate. Here the Sunny side of the temperature can reach 2 000 To - and all because of the short distances to local yellow dwarf, estimated at 0,01560 ± 0,00011 and. E.



Up to the present survey some time there has been an argument about whether the planet is a gas giant type of Neptune, only hot, or it is dominated by heavy elements. After determining the radius of the planet (small) and its significant density version of "hot Neptune" has disappeared, and the scientists stated that this is one of the first (if not the first) of the planets, for which it is safe to say she carbon. The fact that the chemical composition of local stars very little silicon and many carbon - features missing from the Sun.

In addition, observations of the spectrum, almost not found on the surface of Cancer 55 e traces of water. Among other factors, this means that the planet composition very far from the Earth, almost completely covered with water and a silicate mantle. Mantle Cancer 55 e consists mainly of carbon, which accounts for up to a third of its weight. But given the enormous temperatures and pressures inside, it is likely that the mantle consists mainly of diamonds. Even if only two-thirds of the carbon Cancer 55 e are in this form, the diamonds there, by weight, more than double weighs all the Earth.

Detection of the first carbon planet finally puts an end to the issue of whether or not a chemical diversity planets similar in size to the Earth. It is obvious that they are the only question is how chemistry can influence the processes. Although most of the observed yellow dwarf (and their stellar systems) closer to the Sun than to 55 Cancer (rare cormetallis star), simply due to the abundance of stars in the Galaxy can be assumed that carbon planets in her millions, if not billions because one 55 Cancer has at least five planets.

It is already obvious, that such planets may not be in a strong magnetic field (for lack of fluidity substances in the mantle) and plate tectonics (for the same reason). The more interesting question is whether they can be life - certainly, not too hot Cancer 55 e, and on more distant from the sun carbon planets, such as satellites of the same Cancer 55 f, on which surface water can exist in liquid form. If this does occur in such poor water and oxygen worlds, its difference from the earth must be unique.

This study will soon appear in the journal Astrophysical Journal Letters, and with its Preprint available here and now.

Based on the materials of Yale University.