IC 4406: A Seemingly Square Nebula
18.06.2002

How can a round star make a square nebula? This conundrum comes to light when studying planetary nebulae like IC 4406. Evidence indicates that IC 4406 is likely a hollow cylinder, with its square appearance the result of our vantage point in viewing the cylinder from the side.

IC 405: The Flaming Star Nebula
24.11.2003

Rippling dust and gas lanes give the Flaming Star Nebula its name. The red and purple colors of the nebula are present in different regions and are created by different processes. The bright star...

Orion's Horsehead Nebula
25.09.1995

The black indentation to the red emission nebula seen just to the right of center of the above photograph is one of the most famous features in any nebulae on the sky. Because of its shape, it is known as the Horsehead Nebula.

The Crab Nebula in X Rays
29.09.1999

Why does the Crab Nebula still glow? In the year 1054 A.D. a supernova was observed that left a nebula that even today glows brightly in every color possible, across the entire electromagnetic spectrum. At the nebula's center is an ultra-dense neutron star that rotates 30 times a second.

What the Hubble Saw
25.11.2004

In this striking 41 inch by 38 inch quilt, astronomy enthusiast Judy Ross has interpreted some of the Hubble Space Telescope's best galactic and extragalactic vistas. Featured in past APODs, clockwise from...

Shapley 1: An Annular Planetary Nebula
15.02.1997

What happens when a star runs out of nuclear fuel? The center condenses into a white dwarf while the outer atmospheric layers are expelled into space and appear as a planetary nebula. This particular planetary nebula, designated Shapley 1 after the famous astronomer Harlow Shapley, has a very apparent annular ring like structure.

The Nebulous Realm of WR 134
31.05.2024

Made with narrowband filters, this cosmic snapshot covers a field of view over twice as wide as the full Moon within the boundaries of the constellation Cygnus. It highlights the bright edge of a ring-like nebula traced by the glow of ionized hydrogen and oxygen gas.

Shapley 1: An Annular Planetary Nebula
9.08.1998

What happens when a star runs out of nuclear fuel? The center condenses into a white dwarf while the outer atmospheric layers are expelled into space and appear as a planetary nebula. This particular planetary nebula, designated Shapley 1 after the famous astronomer Harlow Shapley, has a very apparent annular ring like structure.

Perseids Over a Little Planet
12.08.2026

It looks like a view from the Little Prince's planet. The featured image is a throwback to the 2024 Perseid meteor shower, surrounded in this projection by the Bieszczady Mountains in Poland. Visible...

APOD: 2026 May 22 Б The Nebulous Realm of WR 134
22.05.2026

This cosmic snapshot covers a field of view over twice as wide as the full Moon within the boundaries of the high-flying constellation Cygnus. Made using astronomical narrowband filters, the image highlights the bright edge of a ring-like nebula traced by the glow of ionized hydrogen and oxygen gas.