A Star Cluster in Motion
30.07.2002

Star clusters are a swarm of complex motions. The stars that compose globular clusters and many open clusters all orbit the cluster center, occasionally interacting, gravitationally, with a close-passing star. The orbits of stars around the cluster are typically not as circular as the orbits of planets in our solar system.

GRO J1655 40: Evidence for a Spinning Black Hole
1.06.2003

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 View Near a Black Hole
19.04.2009

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 Great Russian Meteor of 2013
18.02.2013

What in heaven's blazes is that? Thousands of people living near the Ural Mountains in Russia saw last Friday morning one of the more spectacular meteors of modern times streak across the sky. Forceful sound waves arrived at the ground minutes later, knocking people over and breaking windows for hundreds of kilometers.

Analemma
9.07.2002

If you took a picture of the Sun at the same time each day, would it remain in the same position? The answer is no, and the shape traced out by the Sun over the course of a year is called an analemma.

Venus South Polar Vortex
28.09.2010

What's happening over the South Pole of Venus? To find out, scientists have been studying images taken by the robotic Venus Express spacecraft when it passes over the lower spin axis of Earth's overheated twin.

A Nova In Aquila
15.12.1999

On December 1st, experienced observers patroling the night sky with binoculars noticed what seemed to be a new star in the constellation of Aquila (The Eagle). It wasn't really a new star though.

Saturn Rotates
3.10.2000

The dramatic rotation of the cloud-tops of Saturn every ten-hours is particularly evident from orbit around the gas giant planet. With a good enough telescope, however, such rotation is visible even from Earth, as shown by this time-lapse image sequence from the Hubble Space Telescope taken in November 1990.

In the Center of the Keyhole Nebula
21.07.1997

Stars, like people, do not always go gentle into that good night. The above Keyhole Nebula results from dying star Eta Carinae's violently casting off dust and gas during its final centuries. Eta Carinae is many times more massive than our own Sun, and should eventually undergo a tremendous supernova explosion.

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.