11.   Using the orbiting Chandra X-ray Observatory, astronomers have discovered a new feature in one of the most intensively studied objects in the sky, the Crab nebula.

12.   As astronomers discover more and more near-Earth asteroids, they seek a standardized way of alerting the public to the hazard they might pose.

13.   Astronomers have discovered evidence that hundreds of years ago a star exploded closer to Earth than any other known supernova.

14.   As astronomers discover more and more near-Earth asteroids, they seek a standardized way of alerting the public to what potential hazard they pose.

15.   Astronomers discover new planet.

16.   British astronomers have discovered sporadic small explosions on the surface of the sun that they say may help explain some of its mysteries.

17.   So far, astronomers have discovered stars as old as seven billion years.

18.   A Chinese amateur astronomer has discovered a comet -- the first to be spotted by an amateur observer from China, the official Xinhua news agency said.