A Network of Microlensing Caustics

Explanation: A virtual sky map like this would be of interest to astronomers studying gravitational microlensing. In microlensing , the gravity of stars near the line of sight can act to magnify the light of background objects such as distant stars , or quasars . Nowhere is this magnification greater than near a gravitational lensing caustic . In the above computer simulated map , caustics are discernible as the sharp bright curved lines. When a background quasar moves across a microlensing caustic, it can appear dramatically brighter . Many astronomers thought microlensing events practically immeasurable even ten years ago, but within the past five years now hundreds have been found . Precise measurements of microlensing are now providing unique information about the composition and distribution of matter in galaxies and the universe . Some astronomers now predict that future microlensing searches might even isolate planets orbiting distant stars.