round, expanding shell with intricate, knotty filaments

Stellar Science

Cassiopeia A: A Festive Supernova Remnant

New near-infrared observations from the Webb telescope reveal intricate strands of debris from the exploded star.

Ursa Major Arc

Milky Way

Astronomers Discover Huge Circular Arc Near the Big Dipper

The 30-degree circular arc is likely a shock front expanding from a star that exploded some 100,000 years ago.

The Crab Nebula

Astronomy & Observing News

Blast from the Past in Today’s Sky

Astronomers think they have identified the remnant of a supernova recorded by Chinese astronomers in AD 386.

Gamma-ray emitting supernova remnants

Stellar Science

Gamma-ray Supernova Remnants Shed Light on Cosmic Rays

Astronomers have found the gamma-ray-emitting remains of three exploded stars, and the remnants might reveal the origin of cosmic rays.

Graceful arc of shocked gas

Celestial Objects to Observe

How to See Cygnus's Other Veil Nebula

You'll be entering uncharted territory when you seek out this little known 'Shadow of the Veil' in Cygnus this summer.

Stellar Science

Supernova Remnant in Technicolor

Take a look at this supernova remnant from radio waves to x-rays to see multiple features of its bubble-like expanding shock wave. Supernovae — the dramatic explosions of massive stars ending their lives — can outshine their host galaxies for weeks, allowing them to be seen across millions of light-years…