The discovery of a new, potentially rocky planet, four times larger than ours and very close to Earth, has attracted the attention of scientists around the world in recent hours.
GJ 251 Cas the new “Super Earth” has been renamed, is an exoplanet, that is to say a planet that orbits around a star outside our Solar System: it is located at a distance of just 18.2 light years and orbits around a red dwarf, a small and cold star that is decidedly common in our galaxy, capable of guaranteeing temperate environmental conditions. According to the international team of astronomers led by Penn State University, which made the discovery, it could host on its surface waterfall in a liquid state, considered a necessary condition for the birth of life according to our current knowledge
“We look for these types of planets because they represent our best chance of finding life elsewhere”said Suvrath Mahadevan, professor of astronomy at Penn State University and co-author of an article dedicated to the important discovery published in The Astronomical Journal. “The exoplanet is in the habitable zone or ‘Goldilocks Zone,’ the right distance from its star for liquid water to exist on its surface if it has the right atmosphere.”
The team explained that the discovery of GJ 251 C was the culmination of 20 years of observation of the sky in search of Earth-like planets: the use of the Habitable Zone Planet Finder, an extremely precise infrared spectroscope installed on the Hobby-Eberly telescope at the McDonald Observatory in Texas, was fundamental. This tool takes advantage of a sort of prism to break down the light of a distant star and then analyze it: using the technique known as radial velocity or Doppler method, it is able to verify minimal oscillations in the color of the starlight on the basis of which to identify an orbiting planet responsible for these fluctuations.“We call it the Habitable Zone Planet Finder, because we look for worlds that are at the right distance from their star so that liquid water can be present on their surface. This was the main objective of the investigation”Mahadevan clarified.
The data collected allowed the researchers to improve measurements of the wobble of another already known planet orbiting the star, known as GJ 251 b, which rotates around the red dwarf every 14 days. By combining the information with that obtained from the Habitable-Zone Planet Finder, it was possible to detect a second signal strongest at 54 days. This revealed to experts that there was a second, much more massive planet orbiting the star. Signal confirmed thanks to the NEID spectrometer built by Penn State researchers, connected to a telescope at the Kitt Peak National Observatory in Arizona.
“With this system we are at the forefront of technology and analysis methods”said paper co-author Corey Beard. “We need the next generation of telescopes to directly image this potential Super Earth, but we also need investment from the scientific community.”