The Case of the Missing Supernova
13.04.1999

Would you notice a second Moon in the sky? About 700 years ago, light from a tremendous explosion reached Earth that should have appeared almost as bright as a full Moon. The bright spot should have lasted for weeks, yet no notation of such an occurrence has been found in historical records.

Elements in the Aftermath
1.08.2019

Massive stars spend their brief lives furiously burning nuclear fuel. Through fusion at extreme temperatures and densities surrounding the stellar core, nuclei of light elements ike Hydrogen and Helium are combined to heavier elements like Carbon, Oxygen, etc. in a progression which ends with Iron.

Elements in the Aftermath
26.10.2001

Massive stars spend their brief lives furiously burning nuclear fuel. Through fusion at extreme temperatures and densities surrounding the stellar core, nuclei of light elements like Hydrogen and Helium are combined to heavier elements like Carbon, Oxygen, etc. in a progression which ends with Iron.

N132D and the Color of X Rays
23.05.2002

Supernova remnant N132D shows off complex structures in this sharp, color x-ray image. Still, overall this cosmic debris from a massive star's explosive death has a strikingly simple horseshoe shape. While N132D lies 180,000 light-years distant in the Large Magellanic Cloud, the expanding remnant appears here about 80 light-years across.

High Velocity Clouds and the Milky Way
14.12.1999

Where are these gas clouds going so quickly? High velocity clouds (HVCs) of gas have been seen for decades but their origins and destinations have remained mysterious. Recent measurements have now placed at least...

The Mysterious Rings of Supernova 1987A
31.03.2002

What's causing those odd rings in supernova 1987A? In 1987, the brightestsupernova in recent history occurred in the Large Magellanic Clouds. At the center of the picture is an object central to the remains of the violent stellar explosion.

APOD: 2025 August 8 Б Dawn of the Crab
8.08.2025

One of the all-time historic skyscapes occured in July 1054, when the Crab Supernova blazed into the dawn sky. Chinese court astrologers first saw the Guest Star on the morning of 4 July 1054 next to the star Tianguan (now cataloged as Zeta Tauri).

ASCA X-Ray Observatory
20.02.1996

Today marks the third anniversary of the launch of the Advanced Satellite for Cosmology and Astrophysics (ASCA; renamed from Astro D when launched). ASCA, seen here superposed on galaxy M31, is a Japanese satellite for which NASA has provided some scientific equipment. ASCA carries four large-area X-ray telescopes.

Wisps of the Veil Nebula
4.02.2003

These wisps of gas are all that remain visible of a Milky Way star. Many thousands of years ago that star exploded in a supernova leaving the Veil Nebula, pictured above. At the time...

NGC 7841: The Smoke Nebula in Frustriaus
1.11.2013

NGC 7841 is probably known as the Smoke Nebula, found in the modern constellation of Frustriaus, the frustrated astrophotographer. Only a few light-nanoseconds from planet Earth, The Smoke Nebula is not an expanding supernova remnant along the plane of our Milky Way galaxy, though it does look a lot like one.