Quasars are among the brightest objects in the universe,radiating more energy than entire galaxies! great aren't they? After speculating for years about the mysterious nature of quasars, astronomers had known that they lie at the heart of some galaxies.They draw their energy from enormous black holes which have masses billions of times greater than of our sun.Like cosmic vacuum cleaners these gravitational "MONSTERS" suck up matter from their surroundings,releasing unimaginable quantities of energy in the process.
Light rays are subject to the effects of gravity. If a ray passes close to a star or galaxy its path is curved by an effect known as "GRAVITATIONAL LENSING". This can produce some interesting effects.This is how scientists can observe quasars which would otherwise be hidden from us behind a much closer galaxy. Thanks to this phenomenon, astronomers have discovered several planets orbiting other stars.
Posted by Dheeraj Kumar