In 2003, astronomers discovered a planet outside our solar system by measuring the way light from a distant star warped around the new world's host star.
But it took two more years of telescope observations to actually see the host star. Using NASA's Hubble Space Telescope, astronomers have for the first time identified the parent star of distant planet discovered through gravitational microlensing.
Microlensing is gravitational-lensing of a background object by a compact foreground object. The compact object's gravity bends the light rays from the background object in such a way that the image is magnified. For this to happen, the background and foreground objects must obviously line up near perfectly.
In this case the brightness of the background star masked the light from the foreground star, rendering it virtually invisible. Yet the small 'wobbles' in the microlensed image indicated that a planet was orbiting the foreground star – the lens was shaking a bit!
How they managed to spot the 'invisible' star is expected to appear later this month in Astrophysical Journal Letters. Read a full summary at Space.com
