Scientists have discovered another promising zemplepodobnuyu planet
A total of 11 light-years from the solar system, astronomers have discovered a new Earth-like planet with a climate that can be expected to be suitable for life. It should be noted that after Proxima b is the second nearest to us exoplanet, which has a similar feature. The object was named Ross 128 b, and is located in the habitable zone of its star, the red dwarf Ross 128. Found exoplanet using the ESO HARPS receiver in the La Silla Observatory in Chile. And to open it scholar took a long time.
"We started to observe the star from July 2005", - said the portal ScienceAlert astronomer Nicolas Astudillo-Defra from the Geneva Observatory.
"Since 2013, our observations have become more frequent, and only later, 157 of these observations, we were able to catch a signal strong enough to be able to infer the presence of a planet there."
It has a mass of about 1, 35 times more earth. From this we can conclude that it is hard, because the gaseous planet, at least those of which we know, as a rule, presented by these giants. Another sign indicating the nature of the firm Ross 128 b, is that it is relatively close to its home star - about 20 times closer than Earth is to the Sun - so its orbital period is 9, 9 days. Why it can be potentially suitable for life? It's simple: it is not too hot and at the same time not too cold. Star Ross 128 is a dim red dwarf. It emits less radiation than our sun. According to preliminary calculations, the planet receives only 1, 38 times more energy than the Earth. In addition, the activity of the red dwarf Ross 128, scientists say, is several times lower compared to the average activity of other red dwarfs, for example, the same Proxima Centauri. In other words, the conditions on the planet Ross 128 b may be more stable.
The researchers note that do not yet know whether the Ross 128 b atmosphere. But if it is still there and is similar to, say, Venusian, the equilibrium temperature on its surface in such a case will be about -4 degrees Celsius. If it looks more like the Earth's, its rate will be closer to -60 degrees Celsius. If the atmosphere is thinner, it can be warmed up to +20 degrees Celsius. To know for sure get to the launch of Extremely Large Telescope, whose construction is currently underway. The operation of the telescope promise to introduce by 2024. Its capacity will be simply enormous. So enormous that scientists will be able to search for biomarkers on this and other exoplanets.
Find and collect current information about the planet Ross 128 b was possible thanks to a method for measuring the radial velocities. Currently, the transit method is most often used to search for new exoplanets. In the framework of the definition of a planet occurs at the moment when it is moving in its orbit, it passes in front of the native star, followed by astronomers. When a planet is located between the field of view of the telescope and the star, the brightness of the last few drops. That's what leads to search for new planets, for example, a space telescope "Kepler" has discovered in 2337 confirmed exoplanets. Scientists say that this method is the most efficient and effective, based on the naked figures. Nevertheless, transit search technique has one major drawback. He demands that the planets line up in a straight line from its star so as to block the light of its luminaries, overseen by astronomers. In the case where it is impossible to meet these conditions, the most reliable alternative for determining the presence ekzoplanety is a measurement of the radial velocity.
When a planet orbits a star, it is, of course, does not stand still. Since it has a slight rotation of the gravitational effect on the star, giving it a subtle circular or elliptical motion. In other words, the distance between the Earth and star changes slightly, therefore, changes occur in its spectrum. When it gets closer to Earth, leaving its signature in the blue range of the spectrum. When she, on the contrary, is moving away from the Earth, it goes into the red range. This effect is called the Doppler shift and that its measurements are made using the radial velocities calculation method.
This is a very laborious and difficult work. It is therefore required HARPS receiver decade observations in order to detect exoplanet Ross 128 b.
"Even if we close a star arrangement must deal with a host of side effects and noise in the data. For example, when displaying the data of the dynamics of stellar surface vibration amplitude of signals generated by the stars and planets can be the same, which complicates the task for us in distinguishing these signals "- comments Astudillo-DEFRA.
"We started our monitoring of the star in 2005. Since 2013, the frequency of observations became more intense, and only after 157 of these observations, we finally caught a strong enough signal to the planet. "
As noted above, more about the planet, scientists hope to learn from the introduction to the work of European Extremely Large Telescope.
"We have some ideas about what to look for biomarkers. Of course, they are based only on our knowledge of the Earth. "