The presence of a planet orbiting a distant star has been deduced not by the customary method of observing a slight change in the star's spectrum when tugged by the planet but rather by the way in which a foreground star (17,000 light years away) and its attendant planet distort the image of a background star (some 24,000 light years away) through the process of gravitational lensing. Several detector groups are set up to monitor the passage of stars in the Milky Way passing behind or near foreground objects (dark matter? brown dwarfs? other stars?) and to make sense of changes in the light curve for the background objects.

Ian Bond of the Institute for Astronomy in Edinburgh, Scotland and his colleagues at two detector groups, the Microlensing Observations in Astrophysics (MOA) and Optical Gravitational Lensing Experiment (OGLE) report that in the case of one distant star the characteristic brightening light curve (heralding a lensing event) bore some extra spikes indicative of a lensing object consisting of two parts. Further analysis showed that the one object was only 0.4% as massive as the other, suggesting a star-planet pairing. The presumed planet has a mass of 1.5 Jupiters. (Bond et al., Astrophysical Journal Letters, 10 May 2004.)