APOD: 2025 July 26 Б Globular Cluster Omega Centauri
25.07.2025

Globular star cluster Omega Centauri packs about 10 million stars much older than the Sun into a volume some 150 light-years in diameter. Also known as NGC 5139, at a distance...

Stephan's Quintet from Hubble
2.06.2019

When did these big galaxies first begin to dance? Really only four of the five of Stephan's Quintet are locked in a cosmic tango of repeated close encounters taking place some 300 million light-years away.

ULXs in M74
30.03.2005

In visual appearance, M74 is a nearly perfect face-on spiral galaxy, about 30 million light-years away toward the constellation Pisces. The red blotches seen in this composite view are ultraluminous x-ray sources (ULXs) mapped by the Chandra X-ray Observatory.

The Lynx Arc
4.11.2003

While chasing the spectrum of a mysterious arc in a cluster of galaxies within the obscure northerly constellation Lynx, astronomers have stumbled upon the most massive and distant star-forming region ever discovered. The notably...

Galaxy Cluster in the Early Universe
25.02.2004

Long before medieval alchemists dreamed of transmuting base metals to gold, stellar furnaces in this massive cluster of galaxies - cataloged as RDCS 1252.9-2927 - had transformed light elements into heavy ones. In the false-color composite image individual cluster galaxies can be seen at optical and near-infrared wavelengths, shown in red, yellow, and green colors.

Young Star Clusters in an Old Galaxy
4.07.2002

Elliptical galaxy NGC 4365 is old, probably about 12 billion years old. Like most elliptical galaxies, this galaxy was thought to be full of old stars too, its burst of star forming activity having long since ended.

21st Century M101
13.07.2012

One of the last entries in Charles Messier's famous catalog, big, beautiful spiral galaxy M101 is definitely not one of the least. About 170,000 light-years across, this galaxy is enormous, almost twice the size of our own Milky Way Galaxy.

21st Century M101
5.11.2019

One of the last entries in Charles Messier's famous catalog, big, beautiful spiral galaxy M101 is definitely not one of the least. About 170,000 light-years across, this galaxy is enormous, almost twice the size of our own Milky Way Galaxy.

Dark River Wide Field
19.07.2010

A Dark River of dust seems to run from our Galactic Center, then pool into a starfield containing photogenic sky wonders. Scrolling right will reveal many of these objects including (can you find?)...

Huge Gamma Ray Bubbles Found Around Milky Way
9.11.2010

Did you know that our Milky Way Galaxy has huge bubbles emitting gamma rays from the direction of the galactic center? Neither did anybody. As the data from the Earth-orbiting Fermi satellite began acuminating over the past two years, however, a large and unusual feature toward our Galaxy's center became increasingly evident.