Discovered last year, an object named Ross 128 b is the second nearest Earth-like exoplanet known to science, located some 11 light-years from Earth, which is relatively close in the scale of the universe. Now, thanks to a research published in the Astrophysical Journal Letters, some new exciting details of its structure and composition has been uncovered by simply analyzing the chemical features of the host star.
The second closest temperate exoplanet to Earth
The exoplanet was discovered in 2017 using ESO’s High Accuracy Radial velocity Planet Searcher (HARPS). Orbiting around Ross 128, its host star, Ross 128 b has been the subject of strong interest of scientists due to its Earth-like size and the likeliness of a temperate climate. Ross 128 b is regarded as the second closest exoplanet with temperate climate, with Proxima b, located only four light-years from our planet, being the nearest.
Learning about an exoplanet by analyzing its host star’s components
Aiming to learn more about the conditions on Ross 128 b, Diogo Souto of the Observatório Nacional in Brazil and his team of scientists decided to study the chemical components of its host star. As we know, disks of dust and gas surrounding stars at the early stages of their lives are the building materials of planets, so the star’s composition reflects on those of the resulting planets’ and vice-versa.
Ross 128 b is likely to have a rock surface
With the help of the Sloan Digital Sky Survey’s spectroscopic instrument APOGEE, the spectrum of Ross 128 was examined, showing large amounts of iron, carbon, magnesium, aluminum, calcium, potassium, oxygen and titanium. The researchers then used the star’s magnesium and iron levels to calculate the mass ratio of the planet’s mantel layers and its core. The result was then combined with the star’s chemical composition, showing that Ross 128 b’s radius allows us to place this planet in the group of those with rocky surfaces.
The researchers also measured the temperatures on Ross 128, which proved that Ross 128 b is very likely to have a temperate climate. The red dwarf generates perfect temperatures for its planet, orbiting Ross 128 twenty times closer than the distance between the sun and Earth.
Although we still do not know much about the processes taking place on Ross 128 b, its close distance to Earth means a bigger chance of exciting discoveries in the future.