Using data obtained in 2016 by NASA’s Kepler space telescope, an international team of astrophysicists has discovered a near-identical twin of Jupiter. Located almost 17,000 light-years from Earth, the planet K2-2016-BLG-0005Lb is one of the farthest exoplanets scientists have yet found through gravitational microlensing. It is the first planet to be discovered from space in this way.
To find the planet with gravitational microlensing, the team observed data from Kepler obtained between April and July 2016. They wanted to find evidence for an exoplanet and its host star temporarily bending and magnifying the light from a background star as it passes by the line of sight.
Dr. Eamonn Kerins, Principal Investigator for the Science and Technology Facilities Council (STFC) grant that funded the work, said, “To see the effect requires almost perfect alignment between the foreground planetary system and a background star. The chance that a background star is affected this way by a planet is tens to hundreds of millions to one against. But there are hundreds of millions of stars towards the center of our Galaxy. So Kepler just sat and watched them for three months.”
“Kepler was also able to observe uninterrupted by weather or daylight, allowing us to determine precisely the mass of the exoplanet and its orbital distance from its host star. It is Jupiter’s identical twin in terms of its mass and its position from its Sun, which is about 60% of the mass of our own Sun.”
- D. Specht, R. Poleski, M.T. Penny et al. Kepler K2 Campaign 9: II. First space-based discovery of an exoplanet using microlensing. arXiv:2203.16959