OGLE-2006-BLG-109L (where 'L' stands for lens) is a dim magnitude 17 M0V

galactic bulge In astronomy, a galactic bulge (or simply bulge) is a tightly packed group of stars within a larger star formation. The term almost exclusively refers to the central group of stars found in most spiral galaxies (see galactic spheroid). Bulges w ...

star A star is an astronomical object comprising a luminous spheroid of plasma (physics), plasma held together by its gravity. The List of nearest stars and brown dwarfs, nearest star to Earth is the Sun. Many other stars are visible to the naked ...

approximately 4,920

light-year A light-year, alternatively spelled light year, is a large unit of length used to express astronomical distances and is equivalent to about 9.46 trillion kilometers (), or 5.88 trillion miles ().One trillion here is taken to be 1012 ...

s away in the

constellation A constellation is an area on the celestial sphere in which a group of visible stars forms Asterism (astronomy), a perceived pattern or outline, typically representing an animal, mythological subject, or inanimate object. The origins of the e ...

of Scorpius.

Planetary system

In 2008, two extrasolar planets were discovered around the star using gravitational microlensing. The two planets are at a distance from their star that make them suspected analogs of

Jupiter Jupiter is the fifth planet from the Sun and the List of Solar System objects by size, largest in the Solar System. It is a gas giant with a mass more than two and a half times that of all the other planets in the Solar System combined, but ...

and

Saturn Saturn is the sixth planet from the Sun and the second-largest in the Solar System, after Jupiter. It is a gas giant with an average radius of about nine and a half times that of Earth. It has only one-eighth the average density of Earth; h ...

. The star is surrounded by a

planetary system A planetary system is a set of gravitationally In physics, gravity () is a fundamental interaction which causes mutual attraction between all things with mass or energy. Gravity is, by far, the weakest of the four fundamental interacti ...

consisting of at least two planets: b with a mass of 0.727 of

and c with the mass of approximately 0.271 of

. Their mass ratios, distance ratios, and equilibrium temperatures are similar to those of Jupiter and

in the

Solar System The Solar SystemCapitalization of the name varies. The International Astronomical Union, the authoritative body regarding astronomical nomenclature, specifies capitalizing the names of all individual astronomical objects but uses mixed "Solar S ...

as well as the 47 UMa system. Both planets were discovered simultaneously by gravitational microlensing in a common effort by the Optical Gravitational Lensing Experiment
microFUN
MOA,

PLANET A planet is a large, rounded astronomical body that is neither a star nor its remnant. The best available theory of planet formation is the nebular hypothesis, which posits that an interstellar cloud collapses out of a nebula to create a you ...

and

RoboNet RoboNet-1.0 was a prototype global network of UK-built 2-metre robotic telescopes, the largest of their kind in the world, comprising the Liverpool Telescope on La Palma (Canary Islands), the Faulkes Telescope North on Maui (Hawaii), and the Faulk ...

collaborations, as announced on 14 February 2008. This is the first planetary system where more than one planet was detected using gravitational microlensing.

Planetary system

See also