Jupiter has an identical twin. Einstein helps in finding this new world

Astronomers have discovered an identical twin of Jupiter, which has a similar mass and is at a similar location from its star as Jupiter is from our Sun.

Known for its bright colours and dominated by a massive swirl of storm, Jupiter is a unique world in our Solar System. Astronomers have now found it's not alone and has a near-identical twin which is located at a similar distance from its star as Jupiter is from our Sun.

Dubbed K2-2016-BLG-0005Lb, the exoplanet has been detected by an international team of astrophysicists using data obtained in 2016 by NASA's Kepler space telescope. The telescope has so far detected nearly 2700 planets in the Milky Way galaxy, but this Jupiter-like planet is twice as distant as any seen previously.

Located 17,000 light-years from Earth, scientists used Albert Einstein's Theory of Relativity and a method known as gravitational microlensing to spot this unique world as it temporarily bent and magnified the light from a background star.

The study has been published as a preprint on ArXiv.org and submitted to the journal Monthly Notices of the Royal Astronomical Society.

Led by Jodrell Bank Centre for Astrophysics and PhD student, David Specht from The University of Manchester, the team searched through Kepler data collected between April and July 2016 when it regularly monitored millions of stars close to the centre of the Galaxy.

"To see the effect at all 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 centre of our galaxy. So, Kepler just sat and watched them for three months," Eamonn Kerins, Principal Investigator for the Science and Technology Facilities Council (STFC), who founded the project, said in a statement.

Several teams had been scanning the same patch of sky as Kepler. However, the space-based telescope was faster in picking up the anomaly from its location nearly 135 million kilometres from Earth. Uninterrupted by weather or daylight, the Kepler telescope determines precisely the mass of the exoplanet and its orbital distance from its host star.

It is basically 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, the team said adding that this was the first time the Kepler telescope had discovered a planet using Einstein's microlensing.

"This event is the first bound microlensing exoplanet to be discovered from space-based data. Even though a space telescope is not designed for microlensing studies, this result highlights the advantages for exoplanet microlensing discovery that come from continuous, high-cadence temporal sampling that is possible from space," the team said in its preprint paper.

The Kepler telescope was designed to survey a region of the Milky Way galaxy to discover hundreds of Earth-size and smaller planets in or near the habitable zone and determine the fraction of the hundreds of billions of stars in our galaxy that might have such planets. Working in deep space for nine years, before retiring, Kepler discovered planets from outside the solar system. Many of these planets could be promising places for life.