Last year astronomers announced the discovery of exoplanets is only 11 light years from Earth. And not just another exoplanet, and rocky exoplanets, presumably with great potential for habitability. A new group of researchers conducted a deeper analysis of the open-world and found evidence supporting this assumption. On their findings, astronomers have shared in the journal Astrophysical Journal Letters.
The object was the planet of Ross 128 b, turning around the star Ross 128. A team of astronomers under the leadership of Diogo Sotho from the National Observatory of Brazil notes that the peculiarity of this star was the main cause and opportunity for further research discovered planet.
Using the APOGEE spectrograph mounted on the 2.5-meter wide-angle telescope in the Observatory Apache point (new Mexico, USA) researchers conducted an analysis of the waves near infrared light of a star and using a new method figured out its chemical composition.
“Until recently it was very difficult to get the chemical picture for such type of stars,” — said the scientist.
The star Ross 128 belongs to the class of stars, red dwarfs. This is the most numerous class of stars in our galaxy. It accounts for about 70 percent of all stars in the milky Way. They are colder and smaller than our Sun. Another interesting feature of this type of stars is the fact that near most of them, usually a few exoplanets.
Because red dwarfs is very cool type of star the length of the zone of habitability of their (conditional region in space in which the planets located in it, the conditions are close to conditions on the Ground and will ensure the existence of water in liquid phase) is often much less than the distance from the earth to the Sun.
Most red dwarfs are very active stars. For example, Proxima Centauri, too, is a red dwarf, has beside him exoplanets located in the habitable zone. It is located to the Proxima is much closer than Ross 128 to its star and, most likely, devoid of any life because of the constant flashes at Proxima literally sterilize the surface.
At the same time, Ross 128 was a very rare view of the peaceful red dwarfs with a minimum of flare activity. This in turn makes it located near the planet of Ross 128 b a very interesting target for research. However, the angle the planet’s orbit makes it difficult to direct her observation.
“The ability of the APOGEE setup to measure near infrared light, where the waves Ross 128 most active, were key to the opportunity to conduct this research,” says astronomer Johann Teske from the Carnegie Institute (USA).
“This allowed us to find out some fundamental features of “sampledatabase” planet of Ross 128 b”.
After analyzing wave near-infrared spectrum, the researchers were able to determine how much carbon, oxygen, magnesium, aluminum, potassium, calcium, titanium, and iron can contain a star. And this, in turn, allowed scientists to better understand the features of the planet itself, since the chemical composition of stars during the formation of the planet is somehow reflected in its protoplanetary disk of dust and gas. Subsequently, this effect is reflected in the mineral composition and internal structure of the future of the planet. For example, in a published article, scientists say that the ratio of magnesium, iron and silicon in the chemical composition indicates a characteristic of the speed of rotation of the core rocky planet.
The researchers found that the star Ross 128 has the same level of iron that our Sun. Scientists have been unable to find out the level of the contained silicon, but they noted the presence in its composition of magnesium. Knowing the level of iron and magnesium, scientists can determine the possible minimum value of the kernel size of a planet, i.e. its radius.
According to astronomers, the core of Ross 128 b, most likely bigger than earth, but still is within the size range typical for rocky planets. This confirms that the planet is a gas giant.
Knowledge of the approximate radius of the nucleus has allowed scientists to find out and other features. For example, researchers have determined what amount of light and heat in this case can reach the surface, given the temperature of the star itself. Having established this, the researchers came to the conclusion that the planet is indeed in the habitable zone.
Researchers still do not know much about this world. They don’t know, does it have a magnetic field and atmosphere. If they are still there – it is unknown whether the conditions are favorable for the existence of life. At the same Venus, for example, also has atmosphere, but you’ll fry to a crisp even before reaching the surface.
The study of the planet of Ross 128 b once again confirmed the fact, how difficult is it to study exoplanets detected directly.
“It’s amazing that you can talk about planet we can, the light of its parent star, which contains information on the chemical composition of this system,” says Sotho.
“Although Ross 128 b is not a “twin” of the Earth, it still is of great interest. For example, we would like to know the status of its geological activity. This would strengthen our arguments in favor of the fact that the temperature on its surface may be suitable for the existence of water in liquid form,” concluded the researchers.
Spectral analysis of the nearest exoplanets has increased the potential of its habitability
Nikolai Khizhnyak