Just Gas, Part II

This photo of the galaxy ngc 55 shows the birth and death throes of hundreds of stars. Using a telescope at the Cerro Tololo Observatory in Chile, astronomers have taken the clearest picture ever of bubbles and plumes of hot gas shooting out of another galaxy. It’s the most spectacular example of this type of phenomenon, says Annette Ferguson, a graduate student at Johns Hopkins who made the observations with Jay Gallagher of the University of Wisconsin and Rosemary Wyse of Johns Hopkins. The stars responsible for the fireworks are hotter, more massive, and more short-lived than our sun. And while our sun is probably in the middle of a 10-billion-year life span, these massive stars live just 5 or 10 million years. The three astronomers combined several images to amplify the faint loops and flares seen rising thousands of light-years from the plane of ngc 55, which lies some 5 million light-years from Earth. The vast bubbles, Ferguson says, are gas blown out by supernovas or stellar winds; the jets are being expelled by newly forming giant stars.