Diffraction Spikes: When Stars Look Like Crosses
18.11.1997

Unusual appendages around bright stars are commonplace, but never seem to be mentioned. What are they? First, a telescope brings starlight falling over a large area to a small area. To get at this...

Diffraction Spikes: When Stars Look Like Crosses
15.04.2001

Unusual appendages around bright stars are commonplace, but never seem to be mentioned. What are they? First, a telescope brings starlight falling over a large area to a small area. To get at this...

In Motion: Uranus and Moons
29.11.2021

What's that moving across the sky? A planet just a bit too faint to see with the unaided eye: Uranus. The gas giant out past Saturn was tracked earlier this month near opposition -- when it was closest to Earth and at its brightest.

M45: The Pleiades Star Cluster
8.01.2006

Perhaps the most famous star cluster on the sky, the Pleiades can be seen without binoculars from even the depths of a light-polluted city. Also known as the Seven Sisters and M45, the Pleiades is one of the brightest and closest open clusters.

In the Shadow of the Moon
3.07.2019

On July 2 denizens of planet Earth could stand in the Moon's dark umbral shadow during South America's 2019 total solar eclipse. It first touched down in the Southern Pacific Ocean, east of New Zealand.

M45: The Pleiades Star Cluster
3.09.2012

Perhaps the most famous star cluster on the sky, the Pleiades can be seen without binoculars from even the depths of a light-polluted city. Also known as the Seven Sisters and M45, the Pleiades is one of the brightest and closest open clusters.

NGC 6384: Spiral Beyond the Stars
21.03.2011

The universe is filled with galaxies. But to see them astronomers must look out beyond the stars of our galaxy, the Milky Way. For example, consider this colorful telescopic view of spiral galaxy NGC 6384, about 80 million light-years away in the direction of the constellation Ophiuchus.

The Pleiades Star Cluster
26.12.2003

Perhaps the most famous star cluster on the sky, the Pleiades can be seen without binoculars from even the depths of a light-polluted city. Also known as the Seven Sisters and M45, the Pleiades is one of the brightest and closest open clusters.

The Pleiades Star Cluster
2.01.2005

Perhaps the most famous star cluster on the sky, the Pleiades can be seen without binoculars from even the depths of a light-polluted city. Also known as the Seven Sisters and M45, the Pleiades is one of the brightest and closest open clusters.

A Quasar Portrait Gallery
5.12.1997

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?