November 30, 1999
Massive stars -- upwards of tens of times the mass of the Sun - profoundly affect their galactic environment. Churning and mixing the clouds of gas and dust between the stars, they leave their mark on the compositions and locations of future generations of stars and star systems. Dramatic evidence of this is illustrated in our neighboring galaxy, the Large Magellanic Cloud (LMC), by the above ring shaped nebula, Henize 70 (also known as N70 and DEM301). It is actually a luminous "superbubble" of interstellar gas about 300 light-years in diameter, blown by winds from hot, massive stars and supernova explosions, its interior filled with tenuous hot expanding gas. These superbubbles offer astronomers a chance to explore this crucial connection between the lifecycles of stars and the evolution of galaxies.