A new image from the Chandra X-ray Observatory shows off the power of an exploding star. The sequence of events went like this, astronomers said yesterday:

A massive star ran out of fuel and imploded about 1,000 years ago, crushing the mass of a few suns into an extremely dense neutron star about the size of a city. That triggered an explosion that sent a shock wave into space at more than 5 million mph.

The image of SNR 0540-69.3, as it is known, reveals a central intense white blaze of high-energy particles about 3 light-years across, created by the rapidly rotating neutron star, known as a pulsar. Surrounding the white blaze is a shell of hot gas 40 light-years in diameter that marks the outward progress of the supernova shock wave.

Spinning about its axis 20 times each second, the pulsar generates power equal to 30,000 suns. It generates a magnetic cloud of high-energy particles that is a few light years in diameter. Surrounding the scene is an outer shell of gas heated to 50 million degrees Celsius. The massive star that exploded to create SNR 0540-69.3 was evidently in a region where there was an appreciable amount of gas, astronomers said. The supernova shock wave swept up and heated the surrounding gas and created the extensive hot X-ray shell.

Credit: NASA/CXC/SAO