A Sunspot Up Close
6.11.2005

Why would a small part of the Sun appear slightly dark? Visible above is a close-up picture of a sunspot, a depression on the Sun's face that is slightly cooler and less luminous than the rest of the Sun.

GRO J1655 40: Evidence for a Spinning Black Hole
28.05.2006

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.

Henize 70: A SuperBubble In The LMC
13.06.1998

Stars with tens of times the mass of the Sun profoundly affect their galactic environment. Churning and mixing the interstellar gas and dust clouds they leave their mark in the compositions and locations of future generations of stars and star systems.

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.

A Sunspot Up Close
5.10.1998

Sometimes, small regions of the Sun appear unusually dark. Visible above is a close-up picture of a sunspot, a depression on the Sun's face that is slightly cooler and less luminous than the rest of the Sun.

The Great Nebula in Orion
27.09.2004

The Great Nebula in Orion is a colorful place. Visible to the unaided eye, it appears as a small fuzzy patch in the constellation of Orion. Long exposure, digitally sharpened images like this, however, show the Orion Nebula to be a busy neighborhood of young stars, hot gas, and dark dust.

Micro-Quasar GRS1915 Puffs
2.12.1997

On the far side of our Galaxy, gas clouds explode away from a small black hole. This might seem peculiar, as black holes are supposed to attract matter. But material falling toward a black hole collides and heats up, creating an environment similar to a quasar that is far from stable.

GRO J1655 40: Evidence for a Spinning Black Hole
8.05.2001

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.

A Universe in a Box
21.08.1997

Is this our universe? Possibly. It is one computerized guess of how gas in the universe was distributed billions of years ago, at redshift 3, when the universe was only a quarter of its present age.

Panorama of the Whale Galaxy
17.05.2010

The see the full length of this blue whale, scroll right. NGC 4631 is a big beautiful spiral galaxy seen edge-on at only about 30 million light-years away. This galaxy's slightly distorted wedge shape led to its popular moniker of the Whale galaxy.