Apparently, Jupiter has an (almost) twin: is called K2-2016-BLG-0005Lbis located 17,000 light years from Earth and has in common with our gas giant the mass and distance at which it orbits its star, which instead has a mass equal to about 60% of that of the Sun.
This was discovered by an international group of researchers coordinated by the University of Manchester who was studying the data collected by the Kepler space telescope; launched in 2009 to hunt for exoplanets, after nine years of honorable service he retired because he had run out of propellant that powered the thrusters. Evidently though the information he sent in during these long years of observation still has a lot to tell us.
To be honest, Kepler was designed to search for planets by the transit method, which measures the decrease in light of the host star as the planet passes in front of it; the team of researchers who made the discovery decided to analyze the data collected from a different point of view, that of gravitational microlensing, which instead uses random alignments between stars.
The phenomenon is predicted by the theory of general relativity e occurs when a star in the foreground “passes close” to a more distant star in the background, producing a brief burst of brightness; only a small percentage of these “slow effects” are caused by the planets. As the University of Manchester astronomer Eamonn Kerins explained:
To see the effect, you need near-perfect alignment between the planetary system in the foreground and a star in the background. The chance of a star in the background being affected by a planet in this way is tens to hundreds of millions to one. But there are hundreds of millions of stars towards the center of our galaxy, so Kepler has made himself comfortable and observed them for three months.
Well, in this new light the data made it possible to identify 27 microlensing events in some months of 2016, of which five were unpublished, because they never emerged from the data of other terrestrial telescopes. One of the five was K2-2016-BLG-0005Lb, for which the researchers sifted through data from five other ground-based telescopes that were looking at the same portion of the sky at the same time and found that the exoplanet in question has about 1.1 times the size of the sky. mass of Jupiter and which orbits its star at a distance of 4.4 astronomical units (the average distance of Jupiter from the Sun is 5.2 AU).