Messier 88
30.01.2010

Charles Messier described the 88th entry in his 18th century catalog of Nebulae and Star Clusters as a spiral nebula without stars. Of course the gorgeous M88 is now understood to be a galaxy full of stars, gas, and dust, not unlike our own Milky Way.

At The Core Of M15
17.01.1998

Densely packed stars in the core of the globular cluster M15 are shown in this Hubble Space Telescope (HST) image. The star colors roughly indicate their temperatures - hot stars appear blue, cooler stars look reddish-orange.

The Bubble and M52
8.10.2013

To the eye, this cosmic composition nicely balances the Bubble Nebula at the lower left with open star cluster M52 above it and to the right. The pair would be lopsided on other scales, though.

Sharpless 212 in Hydrogen and Sulfur
18.12.2001

Where do the most massive stars form? Observational evidence indicates that the outskirts of developing open clusters of stars are primary locations. Pictured above is one such open cluster: Sharpless 212. Visible in the image center are massive stars in the open cluster.

Messier 2
19.12.2024

After the Crab Nebula, this giant star cluster is the second entry in 18th century astronomer Charles Messier's famous list of things that are not comets. M2 is one of the largest globular star clusters now known to roam the halo of our Milky Way galaxy.

APOD: 2025 October 21 Б IC 1805: The Heart Nebula
21.10.2025

What electrifies the Heart Nebula? First, the large emission nebula on the left, catalogued as IC 1805, looks somewhat like a human heart. The nebula glows brightly in red light emitted by its most prominent element, hydrogen, but this long-exposure image was also blended with light emitted by sulfur (yellow) and oxygen (blue).

The Bubble and M52
14.09.2011

To the eye, this cosmic composition nicely balances the Bubble Nebula at the lower right with open star cluster M52. The pair would be lopsided on other scales, though. Embedded in a complex...

M16: Dust and an Open Cluster
1.11.1995

The photogenic M16 shown above is composed of a young star cluster and a spectacular emission nebulae lined with distinct regions of interstellar dust. Most of the stars in the cluster can be seen offset just above and to the right of the photograph's center.

The Galactic Core in Infrared
17.01.2015

What's happening at the center of our Milky Way Galaxy? To help find out, the orbiting Hubble and Spitzer space telescopes have combined their efforts to survey the region in unprecedented detail in infrared light. Milky Way's center because visible light is more greatly obscured by dust.

APOD: 2008 April 2- Globular Cluster M55 from CFHT
2.04.2008

The fifty-fifth entry in Charles Messier's catalog, M55 is a large and lovely globular cluster of around 100,000 stars. Only 20,000 light-years away in the constellation Sagittarius, M55 appears to earth-bound observers to be nearly 2/3 the size of the full moon.