M82 After the Crash
12.03.2001

When did the Cigar Galaxy light up? Evidence indicates how M82, the Cigar Galaxy, became so bright and peculiar: it collided with neighboring galaxy M81. Astronomers become detectives, however, when trying to figure out when this collision occurred.

NGC 3621: Far Beyond the Local Group
5.06.2002

Far beyond the local group of galaxies lies NGC 3621, some 22 million light-years away. Found in the serpentine southern constellation Hydra, the loose spiral arms of this gorgeous island universe are loaded with luminous young star clusters and dark dust lanes.

Seven Sisters Versus California
18.06.1996

In the lower left corner, dressed in blue, is the Pleiades. Also known as the Seven Sisters and M45, the Pleiades is one of the brightest and most easily visible open clusters on the sky. The Pleiades contains over 3000 stars, is about 400 light years away, and only 13 light years across.

The Cat's Eye Nebula (Revisited)
4.07.1996

Three thousand light years away, a dying star throws off shells of glowing gas. This image from the Hubble Space Telescope reveals "The Cat's Eye Nebula" to be one of the most complex planetary nebulae known.

A Network of Microlensing Caustics
15.12.2002

A virtual sky map like this would be of interest to astronomers studying gravitational microlensing. In microlensing, the gravity of stars near the line of sight can act to magnify the light of background objects such as distant stars, or quasars. Nowhere is this magnification greater than near a gravitational lensing caustic.

Horizon to Horizon
21.12.2007

Scroll right and journey from horizon to horizon as your gaze sweeps through the zenith in the night sky over Beg-Meil, France. Recorded on December 13th, the entertaining panorama (image key) covers 210 degrees in 21 separate exposures, beginning on the beach with bright star Sirius rising in the southeast.

Thor s Emerald Helmet
17.01.2008

This helmet-shaped cosmic cloud with wing-like appendages is popularly called Thor's Helmet. Heroically sized even for a Norse god, Thor's Helmet is about 30 light-years across. In fact, the helmet is actually...

The North America and Pelican Nebulae
30.06.2009

Here are some familiar shapes in unfamiliar locations. This emission nebula on the left is famous partly because it resembles Earth's continent of North America. To the right of the North America Nebula, cataloged as NGC 7000, is a less luminous nebula that resembles a pelican dubbed the Pelican Nebula.

APOD: 2024 September 18 Б The Mermaid Nebula Supernova Remnant
18.09.2024

New stars are born from the remnants of dead stars. The gaseous remnant of the gravitational collapse and subsequent death of a very massive star in our Milky Way created the G296.5+10.0 supernova remnant, of which the featured Mermaid Nebula is part.

The Brown Dwarfs of Orions Trapezium
30.08.2000

The bright stars above are well known as heart of the Trapezium, an open cluster of stars in the center of the Orion Nebula. The many dim objects, however, are not well known, and have come to attention only on recent images in infrared light.