NASA’s Hubble Space Telescope and the W M Keck Observatory in Hawaii made independent confirmations of the exoplanet orbiting far from its central star.
The discovery confirmed the existence of a Uranus-sized exoplanet orbiting far from its central star, through a technique called gravitational microlensing.
Microlensing technique can find distant and colder planets in long-period orbits that other methods cannot detect. It occurs when a foreground star amplifies the light of a background star that momentarily aligns with it. If the foreground star has planets, then the planets may also amplify the light of the background star, but for a much shorter period of time than their host star.
The exact timing and amount of light amplification can give clues to the nature of the foreground star and its accompanying planets.
The system, classified as OGLE-2005-BLG-169, was discovered in 2005 by the Optical Gravitational Lensing Experiment (OGLE), the Microlensing Follow-Up Network
(MicroFUN), and members of the Microlensing Observations in Astrophysics (MOA) collaborations.
Without conclusively identifying and characterizing the foreground star, however, astronomers have had a difficult time determining the properties of the accompanying planet.
Using Hubble and the Keck Observatory, two teams of astronomers have found that the system consists of a Uranus-sized planet orbiting about 370 million miles from its parent star, slightly less than the distance between Jupiter and the Sun. The host star is about 70 per cent as massive as our Sun.