The center of our galaxy is less than 30,000 light years away, but it is notoriously difficult to observe.
Four of a Kind
One of the most popular constellations is Orion the hunter. In the sword of Orion, just below the belt is a nebula known as the Orion Nebula. This nebula is a stellar nursery about 1300 light years away. At the heart of the Orion Nebula is a small cluster of very bright stars known as the Trapezium Cluster. Because Trapezium is bright and reasonably close to us, we’re able to make very precise measurements of the stars’ speed and motion. What we find is a bit of a puzzle.
Mutual Attraction
Part 2 in the equations series. How Newton united physics and astronomy, and brought us face to face with one of the most mysterious and terrifying objects in the universe.
Point of View
Quasars, blazars, and radio galaxies are all related. It just depends upon your point of view.
Quasar, Quasar, Burning Bright
Quasars are among the most energetic things in the universe, and are intense sources of radio waves and visible light. They typically have large redshifts, and are therefore very far away. Although they can be thousands of times brighter than the entire Milky Way galaxy, the source of their energy is relatively small, a fraction of our galaxy’s size.
I’ll Drink to That
There’s a simple calculation that shows the average density of a black hole can be less than water.
Black Holes, Brownian Motion
The supermassive black hole in the center of our galaxy has something in common with a hot cup of tea.
Black Holes
Black holes are objects that are so dense that not even light can escape them. But that’s only if you get too close.
Heart of the Dragon
We can observe the motion of stars in the center of our galaxy, and it is clear from their motion that our galaxy has a supermassive black hole.