Astronomers from the University of Canterbury have discovered an incredibly rare Super-Earth planet located towards the center of the galaxy. The scientists say the planet is only one of a handful that have been discovered with both size and orbit comparable to that of the Earth. UC researchers Doctor Antonio Herrera Martin and Associate Professor Michael Albrow are part of an international team who collaborated to discover the planet.
Martin was the lead author of the paper describing the discovery. He says that the time it took to observe the magnification due to the host star was approximately five days. The planet was detected only during a small five-hour distortion. The host star for the Supra-Earth is about 10% the mass of our sun.
Scientists estimate the planet has a mass somewhere between that of Earth and Neptune. It orbits at a location between Venus and Earth from its parent star. With the mass of the host star the Super-Earth orbits, a year on the planet would be approximately 617 days. The new planet is notable because it’s one of only a handful of extra-solar planets that have been detected with sizes and orbits close to that of Earth.
Scientists discovered the planet using a technique called gravitational microlensing. The microlensing effect is rare, with only about one in a million stars in the galaxy being affected at any given time. Martin noted that this type of observation does not repeat, making the probability of catching a planet at the same time extremely low.
The microlensing event that allowed the discovery of this planet happened in 2018. It was independently detected by the Optical Gravitational Lensing Experiment using a telescope located in Chile and the Korea Microlensing Telescope Network. Those experiments can detect about 3000 microlensing events each year.