M3: Half A Million Stars
17.09.1999

This immense ball of half a million stars older than the sun lies 30,000 light-years above the plane of our Galaxy. Cataloged as M3 (and NGC 5272), it is one of about 250 globular star clusters which roam our galactic halo.

Blue Comet in the Hyades
18.01.2018

Stars of the Hyades cluster are scattered through this mosaic spanning over 5 degrees on the sky toward the constellation Taurus. Presently cruising through the Solar System, the remarkably blue comet C/2016 R2 PanSTARRS is placed in the wide field of view using image data from January 12.

APOD: 2025 August 13 Б Trapezium: In the Heart of Orion
13.08.2025

What lies in the heart of Orion? Trapezium: four bright stars, that can be found near the center of this sharp cosmic portrait. Gathered within a region about 1.5 light-years in radius, these stars dominate the core of the dense Orion Nebula Star Cluster.

White Dwarf Stars Cool
10.09.2000

Diminutive by stellar standards, white dwarf stars are also intensely hot ... but they are cooling. No longer do their interior nuclear fires burn, so they will continue to cool until they fade away. This Hubble Space Telescope image covers a small region near the center of a globular cluster known as M4.

M8: In the Center of the Lagoon Nebula
3.01.2001

In the center of the Lagoon Nebula one finds glowing gas, star clusters, and dense knots of gas and dust just now forming stars. The young open cluster of stars, designated NGC 6523, can be seen in the center of the above image. These stars emit energetic light that ionizes the surrounding hydrogen gas.

APOD: 2025 January 27 Б Pleiades over Half Dome
27.01.2025

Stars come in bunches. The most famous bunch of stars on the sky is the Pleiades, a bright cluster that can be easily seen with the unaided eye. The Pleiades lies only about 450 light years away, formed about 100 million years ago, and will likely last about another 250 million years.

SN Requiem: A Supernova Seen Three Times So Far
2.11.2021

We've seen this same supernova three times -- when will we see it a fourth? When a distant star explodes in a supernova, we're lucky if we see it even once.

Planetary Nebula NGC 2438
7.04.2011

NGC 2438 is a planetary nebula, the gaseous shroud cast off by a dying sunlike star billions of years old whose central reservoir of hydrogen fuel has been exhausted. About 3,000 light-years distant it lies within the boundaries of the nautical constellation Puppis.

Irregular Galaxy Sextans A
14.11.1997

Grand spiral galaxies often seem to get all the glory. Their newly formed, bright, blue star clusters found along beautiful, symmetric spiral arms are guaranteed to attract attention. But small irregular galaxies form stars too, like this lovely, gumdrop-shaped galaxy, Sextans A.

The Rosette Nebula
14.02.2012

The Rosette Nebula is not the only cosmic cloud of gas and dust to evoke the imagery of flowers -- but it is the most famous. At the edge of a large molecular cloud...