The core of a star

The Chandra space observatory, launched last month by the US National Aeronautical and Space Administration, has already started transmitting images. It has sent images of the heart of the Crab Nebula, a star that exploded in the 11 century, which was recorded by Chinese astronomers. The images show energetic material spinning in swirls around the stellar corpse at the nebula's centre. They reveal a bright ring that might be the long-sought power source pumping energy into the pulsar at the centre of the nebula ( Science , Vol 286, No 5438).