Milky Way: Types of Stars
The Milky Way contains both the so-called type I stars, brilliant, blue stars; and type II stars, giant red stars. Blue stars tend to be younger because they burn furiously and use up all of their fuel within a few tens of millions of years. Red stars are usually older, and use their fuel at a slower rate that they can sustain for tens of billions of years. The central Milky Way and the halo are largely composed of the type II population. Most of this region is obscured behind dust clouds, which prevent visual observation. Astronomers have been able to detect light from this region at other wavelengths in the electromagnetic spectrum, however, using radio and infrared telescopes and satellites that detect X rays . Such studies indicate compact objects near the galactic center, probably a massive black hole . A black hole is an object so dense that nothing, not even light, can escape its intense gravity. The center of the galaxy is home to clouds of antimatter particles, which reveal t...