Galactic Central

Our home galaxy, the Milky Way, is a pretty big place. Just one arm of this vast celestial pinwheel, the Orion arm, contains the Earth, the Sun, and almost all the stars we see. We, and all these stars, live on the outskirts of this pinwheel, twenty-five thousand light years from the center.

The center, obscured from sight by the dust of the Great Sagittarius Cloud, lies in the direction of the constellation Sagittarius. Not in that constellation, though - the stars of that constellation lie in our own arm of the galaxy. But if you look at the teapot of Sagittarius, low in the south, youčre looking in the right direction.

Galactic Central! What a crowded place it is. Ten million stars in a region roughly fifty light years in diameter. By contrast, a similar region centered at the Sun contains only a few hundred stars. If we lived in that center, wečd see millions of stars, each as bright as Sirius. The combined starlight would be equal to two hundred full moons. It would never get really dark.

And at the very center of the center? No one knows, but we constantly receive a stream of X-rays from that center. Gasses rushing into a supermassive black hole, millions of times larger than the Sun are heated by friction. It is these gasses that emit the X-rays, and it is this black hole that holds the galaxy together.

(05/28/08)