Three Galaxies in Draco
1.07.2023

This tantalizing trio of galaxies sometimes called the Draco Group, is located in the northern constellation of (you guessed it) Draco, the Dragon. From left to right are face-on spiral NGC 5985, elliptical galaxy...

Millions of Stars in Omega Centauri
29.05.2014

Globular star cluster Omega Centauri, also known as NGC 5139, is some 15,000 light-years away. The cluster is packed with about 10 million stars much older than the Sun within a volume about...

ROSAT Explores The X-Ray Sky
8.10.1996

Launched in 1990, the orbiting ROSAT observatory explored the Universe by viewing the entire sky in x-rays - photons with about 1,000 times more energy than visible light. This ROSAT survey produced the sharpest, most sensitive image of the x-ray sky to date.

Fermi s Gamma Ray Sky
21.03.2009

Scanning the entire sky in gamma-rays, photons with over 50 million times the energy of visible light, the Fermi mission's Large Area Telescope (LAT) explores the high-energy universe. This all-sky map constructed from...

M46 And NGC 2438: Young And Old
5.03.1999

Galactic or open star clusters are relatively young. These swarms of bright stars are born near the plane of the Milky Way, but their numbers steadily dwindle as cluster members are strewn through the Galaxy by gravitational interactions.

APOD: 2026 May 13 Б NGC 188: Old Cluster in the New General Catalog
13.05.2026

The New General Catalog of star clusters and nebulae really isn't so new. In fact, it was published in 1888 - an effort by J. L. E. Dreyer to consolidate the work of astronomers William, Caroline, and John Herschel along with others into a useful single, complete catalog of astronomical discoveries and measurements.

ROSAT Explores The X-Ray Sky
19.08.2000

Launched in 1990, the orbiting ROSAT observatory explored the Universe by viewing the entire sky in x-rays -- photons with about 1,000 times more energy than visible light. This ROSAT survey produced the sharpest, most sensitive image of the x-ray sky to date.

Millions of Stars in Omega Centauri
15.06.2011

Featured in this sharp telescopic image, globular star cluster Omega Centauri (NGC 5139) is some 15,000 light-years away. Some 150 light-years in diameter, the cluster is packed with about 10 million stars much older than the Sun.

Stars Young and Old
26.03.2009

Galactic or open star clusters are relatively young. These swarms of stars are born near the plane of the Milky Way, but their numbers steadily dwindle as cluster members are strewn through the Galaxy by gravitational interactions.

Millions of Stars in Omega Centauri
31.03.2010

Featured in the sharp telescopic image, globular star cluster Omega Centauri (NGC 5139) is some 15,000 light-years away and 150 light-years in diameter. Packed with about 10 million stars much older than...