Super-Earth is a concept for only planets outside the Solar System (or exoplanets) that have a thin surface of rocky soil and atmosphere, with masses several times larger than several dozen times that of Earth, but still smaller than with gas planets like Uranus and Neptune.
Most recently, scientists at the University of Canterbury (New Zealand) have discovered an extremely rare super Earth. Located at the center of the Milky Way galaxy, about 25,000 light-years from Earth, this super Earth is called OGLE-2018-BLG-0677. It is also one of the few exoplanets with Earth-like features located at the farthest distance ever discovered.
Super-Earths usually have masses several times that of Earth, with a rocky surface and thin atmosphere
According to calculations by astronomers, OGLE-2018-BLG-0677Lb has about four times the mass of Earth. It orbits a dwarf star, which is only 10% the size of the Sun. This exoplanet is much closer to its host than Earth, with a distance equivalent to the distance from Venus to the Sun. A year on this exoplanet is about 617 days long.
It is known that astronomers discovered OGLE-2018-BLG-0677Lb is also very special. Normally, exoplanets are usually detected by the transit signal search technique. This is a method of measuring changes in light as exoplanets pass through the host star, helping astronomers detect their existence. However, the detection of OGLE-2018-BLG-0677 by this method is difficult because its transit signal is too weak.
Therefore, the researchers used a technique called “gravitational amplification” (microlensing), which measures the distortion of light as one star moves across in front of another star when viewed from the left. land. This is an extremely rare event in the universe, when light from the farther star is amplified under the influence of the gravitational force of the nearby star according to Albert Einstein’s general theory of relativity.
The light amplification effect helps scientists detect OGLE-2018-BLG-0677
“The combined gravity of the planet and the host star causes the light from the distant background star to amplify in a special way. We use telescopes around the world to measure the bending effect of light“said Dr. Antonio Herrera Martin, head of research at the University of Canterbury (New Zealand).
“The light amplification effect is considered to be extremely rare because only about 1 in 100,000,000 stars in the galaxy is affected by this effect. We may not always be able to observe based on this effect. In addition, the probability of detecting planets at the same time is extremely low“, he added.
Up to now, only 90 exoplanets have been discovered through gravitational amplification. OGLE-2018-BLG-0677Lb is one of these, making it the most rare Super Earth ever.
Refer to LiveScience