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.