Black Holes Are Black
19.01.2001

Q: Why are black holes black? A: Because they have an event horizon. The event horizon is that one-way boundary predicted by general relativity beyond which nothing, not even light, can return. X-ray astronomers...

A Lonely Neutron Star
28.11.1998

How massive can a star get without imploding into a black hole? These limits are being tested by the discovery of a lone neutron star in space. Observations by the Hubble Space Telescope have...

Black Holes in Galactic Centers
17.10.1999

Do all galaxies have black holes at their centers? Although not even a single galaxy has yet been proven to have a central black hole, the list of candidates continues to increase. Results...

Two Black Holes Dancing in 3C 75
9.11.2008

What's happening at the center of active galaxy 3C 75? The two bright sources at the center of this composite x-ray (blue)/ radio (pink) image are co-orbiting supermassive black holes powering the giant radio source 3C 75.

Accretion Disk Simulation
12.03.2005

Don't be fooled by the familiar pattern. The graceful spiral structure seen in this computer visualization does not portray winding spiral arms in a distant galaxy of stars. Instead, the graphic shows spiral...

Accretion Disk Simulation
27.09.2002

Don't be fooled by the familiar symmetry. The graceful spiral structure seen in this computer visualization does not portray winding spiral arms in a distant galaxy of stars. Instead, the graphic shows spiral...

Animation: Spiral Disk around a Black Hole
20.08.2019

What would it look like to orbit a black hole? Many black holes are surrounded by swirling pools of gas known as accretion disks. These disks can be extremely hot, and much of the orbiting gas will eventually fall through the black hole's event horizon -- where it will never been seen again.

Trapezium: At the Heart of Orion
5.08.2018

Near the center of this sharp cosmic portrait, at the heart of the Orion Nebula, are four hot, massive stars known as the Trapezium. Gathered within a region about 1.5 light-years in radius, they dominate the core of the dense Orion Nebula Star Cluster.

Two Black Holes Merge
12.02.2016

Just press play to watch two black holes merge. Inspired by the first direct detection of gravitational waves by LIGO, this simulation video plays in slow motion but would take about one third of a second if run in real time.

The View Near a Black Hole
23.03.2014

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.