Sgr A*: Fast Stars Near the Galactic Center
14.01.2007

Why are these stars moving so fast? Shown above is a time-lapse movie in infrared light detailing how stars in the central light-year of our Galaxy have moved over the past eight years.

A Quasar Portrait Gallery
9.03.2002

Quasars (QUASi-stellAR objects) lie near the edge of the observable Universe. Discovered in 1963, astronomers were astounded that such objects could be visible across billions of light-years, as this implies they must emit prodigious amounts of energy. Where does the energy come from?

Wind from a Black Hole
1.07.2006

Binary star system GRO J1655-40 consists of a relatively normal star about twice as massive as the Sun co-orbiting with a black hole of about seven solar masses. This striking artist's vision of the exotic binary system helps visualize matter drawn from the normal star by gravity and swirling toward the black hole.

Orbiting a Black Hole
1.07.2013

What would it look like to orbit a black hole? Since the strong gravity of the black hole can significantly alter light paths, conditions would indeed look strange. For one thing, the entire sky would be visible, since even stars behind the black hole would have their light bent to the observer's eye.

Circling a Black Hole at its Photon Sphere
2.07.2013

What would it look like to go right up to a black hole? One particularly interesting place near a black hole is its photon sphere, where photons can orbit in circles, a sphere 50 percent further out than the event horizon.

GRO J1655 40: Evidence for a Spinning Black Hole
5.09.2010

In the center of a swirling whirlpool of hot gas is likely a beast that has never been seen directly: a black hole. Studies of the bright light emitted by the swirling gas frequently indicate not only that a black hole is present, but also likely attributes.

The Center of Centaurus A
7.11.2010

A fantastic jumble of young blue star clusters, gigantic glowing gas clouds, and imposing dark dust lanes surrounds the central region of the active galaxy Centaurus A. This mosaic of Hubble Space Telescope images taken in blue, green, and red light has been processed to present a natural color picture of this cosmic maelstrom.

Distant Galaxies in Radio Vision
8.02.2001

Radio waves, like visible light, are electromagnetic radiation and radio telescopes can "see" -- their signals translated into radio images of the cosmos. While individually even the largest radio telescopes have very blurry vision compared to their optical counterparts, networks of radio telescopes can combine signals to produce sharper pictures.

The Holographic Principle
13.09.2009

Is this picture worth a thousand words? According to the Holographic Principle, the most information you can get from this image is about 3 x 10 65 bits for a normal sized computer monitor.

Too Close to a Black Hole
10.12.2000

What would you see if you went right up to a black hole? Above are two computer generated images highlighting how strange things would look. On the left is a normal star field containing the constellation Orion. Notice the three stars of nearly equal brightness that make up Orion's Belt.