NGC 6369: A Donut Shaped Nebula
18.05.1998

Why isn't the star in the center of the nebula? NGC 6369 appears to be a fairly ordinary planetary nebula. It can be seen with a good telescope in the constellation of Ophiuchus. The gas expelled by the central star is bunched in the shape of a donut or cylinder.

Nebula Nova Cygni Turns On
16.12.1996

Old photographs show no evidence of the above nebula. In 1992, a white dwarf star in Cygnus blew off its outer layers in a classical nova explosion: an event called Nova Cygni 1992. Light flooded the local interstellar neighborhood, illuminated this existing gas cloud, excited the existing hydrogen, and hence caused the red emission.

NGC 1977: Blue Reflection Nebula in Orion
1.02.1998

The Orion Nebula is visible to the unaided eye as a fuzzy patch near the famous belt of three stars in the constellation Orion. The above picture captures a part of the Orion Nebula that primarily reflects light from bright Orion stars.

M17: The Omega Nebula
26.01.1999

The Omega Nebula contains glowing gas, dark dust, and some unusually massive stars. Also known as the M17 and the Swan Nebula, the Omega Nebula is about 5000 light-years away, 20 light-years across, and visible with binoculars in the constellation of Sagittarius.

M8: The Lagoon Nebula
7.07.1998

The bright Lagoon Nebula is home to a diverse array of astronomical objects. Particularly interesting sources include a bright open cluster of stars and several energetic star-forming regions. The general red glow is caused by luminous hydrogen gas, while the dark filaments are caused by absorption by dense lanes of dust.

The Great Nebula in Orion
27.01.1998

The Great Nebula in Orion can be found just below and to the left of the easily identifiable belt of three stars in the popular constellation Orion. This fuzzy patch contains one of the closest stellar nurseries, lying at a distance of about 1500 light years.

Meropes Reflection Nebula
15.02.2012

Reflection nebulas reflect light from a nearby star. Many small carbon grains in the nebula reflect the light. The blue color typical of reflection nebula is caused by blue light being more efficiently scattered by the carbon dust than red light.

Star Cluster in the Rosette Nebula
22.05.1996

Embedded in the center of the colorful and photogenic Rosette Nebula is a bright, young open cluster. The bright blue stars in this cluster, labelled NGC 2244, emit ultraviolet light that knocks electrons away from hydrogen atoms.

APOD: 2025 December 29 Б M1: The Crab Nebula
29.12.2025

This is the mess that is left when a star explodes. The Crab Nebula, the result of a supernova seen in 1054 AD, is filled with mysterious filaments. The filaments are not only tremendously...

The Gum Nebula Supernova Remnant
7.11.2000

Because the Gum Nebula is the closest supernova remnant, it is actually hard to see. Spanning 40 degrees across the sky, the nebula is so large and faint it is easily lost in the din of a bright and complex background.