spacetoday.net: Astronomers discover distant exoplanet

Posted: Sat, Apr 17, 2004, 12:54 AM ET (0454 GMT)
Exoplanet microlensing illustration (NASA)

Astronomers announced this week that they have used a new technique to discover an extrasolar planet much farther from Earth than any other known exoplanet. Astronomers said Thursday that they have discovered a planet about 1.5 times the mass of Jupiter orbiting 3 AUs from a red dwarf star 17,000 light-years from the Earth. The discovery was made possible through a technique called gravitational microlensing, where the gravity of an intervening object acts as a magnifying lens, making more distant background stars appear brighter. In this case the exoplanet was directly in the line-of-sight between the Earth and a star 24,000 light-years away, brightening that star momentarily as it passed in front of it. Astronomers hope to use this technique to find many more exoplanets, including worlds as small as the Earth.