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A supernova is a violent stellar explosion that can shine as brightly as an entire galaxy of billions of normal stars. Astronomers divide supernovae into two primary groups: Type Ia and Type II. Type Ia supernovae form as a white dwarf “steals” hot gas from a companion star. If enough gas piles up on the surface of the white dwarf, a runaway thermonuclear explosion blasts the star to bits, leaving nothing behind. These are the brightest supernovae, and can be used to measure the distances to other galaxies. A Type II supernova is the final stage in the evolution of a star that is at least eight times as massive as the Sun. Such a star reaches a point where it can no longer produce nuclear energy in its core. Without the outward pressure created by this energy, gravity wins out and causes the star’s core to collapse to form a neutron star or black hole. The star’s outer layers “rebound” violently, blasting into space at several percent of the speed of light.

Radio Programs

Safe Neighborhood A safe neighborhood in the Milky Way July 27, 2021

IC 10 X-1 A bright, dark star system July 22, 2021

Moon and Antares An upcoming change in the night sky June 22, 2021

Mile Markers Mile markers in the distant universe April 21, 2021

Explosive Change The possible influence of exploding stars April 9, 2021

Final Days Turning up the stellar oven April 8, 2021

Future Blasts Bright stars with brighter futures April 7, 2021

Mystery Explosion An “in-between” stellar explosion March 6, 2021

Faint Ripples Rippling across the galaxy February 22, 2021

Seeing Red Painting the universe red January 9, 2021

Bellatrix Pondering the fate of a giant star January 4, 2021

Big Fireworks II Death from a dying star December 30, 2020

Big Fireworks Big fireworks in the night sky December 29, 2020

Moon and Spica A star with a fiery future December 9, 2020

More Cassiopeia A Forging big batches of chemical elements October 27, 2020

Cassiopeia A Muffling the death of a star October 26, 2020

Cygnus Superbubble Blowing a giant “bubble” in space August 30, 2020

VX Sagittarii A monster among monsters August 18, 2020

Sadr Playing tricks in the night sky August 13, 2020

Red Square A star’s beautiful demise July 7, 2020

Lupus Exploding stars in the wolf June 27, 2020

Speedy Stars Sending a star on a wild ride May 14, 2020

Moon and Antares The amazing fate of a supergiant May 8, 2020

Galactic Fireworks Fireworks from a modest galaxy April 12, 2020

Vela Supernova Inflating a giant bubble April 11, 2020

Mintaka Big stars with bigger futures March 13, 2020

Crab Pulsar Spinning up a dead star February 11, 2020

Adhara Outshining the Dog Star January 31, 2020

Land of the Supergiants The land of the supergiants January 4, 2020

Moon and Spica A star’s busy final day December 19, 2019

Moon and Spica A bright star with a brighter future November 22, 2019

Veil Nebula Unveiling a cosmic explosion August 30, 2019

Apep A “chaotic” star system August 15, 2019

Gamma-Ray Bursts Giant cosmic “death rays” August 14, 2019

Cygnus The impressive heart of the swan July 10, 2019

More Transients Explaining some bright flashes April 28, 2019

Supernova vs. Megalodon Supernova versus Megalodon February 15, 2019

Lepus Hopping after the celestial rabbit February 3, 2019

Navi A bright, busy star system January 21, 2019

Watchman Nuclear reactors and exploding stars August 21, 2018

Cobalt A bit of alchemy from the stars August 3, 2018

Future Supernova Impending doom for a giant star August 2, 2018

Chemistry Set Forging the table of the elements July 18, 2018

Deadly Blasts Zapping the neighbors with energy July 16, 2018

Future Supernova A busy star with a violent future June 5, 2018

Crab Nebula Sculpting an interstellar crab April 19, 2018

More ‘O’ Stars Big stars with a big influence April 13, 2018

Bright Quartet A fascinating stellar quartet April 11, 2018

Pulsars II “Dead” stars that spin like crazy November 28, 2017

Rho Cassiopeia Practicing for a big blast November 22, 2017

Future Blast A future blast from a galactic neighbor October 27, 2017

Feedback Slowing down the stellar birth rate September 8, 2017

Zone of Death A cosmic “zone of death” August 31, 2017

Hyperactive Galaxy A galaxy with lots of fireworks August 22, 2017

Sigma Scorpii Impressive stars near the scorpion’s heart July 30, 2017

Alpha Lupi A bright star with a brighter future July 7, 2017

More Northern Crown The “re-death” of two dead stars May 28, 2017

Spying on Supernovae Keeping many eyes on exploding stars May 22, 2017

Moon and Spica Different fates for stellar siblings May 8, 2017

Making Elements IV Violent alchemy in the stars March 9, 2017

Supernova 1987A III Keeping an eye on a dead star February 24, 2017

Supernova 1987A II Catching “ghosts” from an exploding star February 23, 2017

Supernova 1987A Looking for a hidden star February 22, 2017

Neutron Stars Crushing the core of a mighty star February 20, 2017

Super Supernovae II Explaining a brilliant explosion January 17, 2017

Super Supernovae Making a super-duper supernova January 16, 2017

Betelgeuse Explodes Death gets closer for a giant star December 30, 2016

Cosmic Rays The calling cards of exploding stars November 28, 2016

Explosive Debris Heavy “rains” from exploding stars August 22, 2016

The Stinger Getting a “sting” from the scorpion July 23, 2016

Bright and Brighter Boosting the “boom” of an exploding star June 7, 2016

Puppis Breaking up a mighty ship March 26, 2016

Stellar Whopper The brightest of the bright March 22, 2016

Aludra The showiest “dog” star of all January 13, 2016

The Dog’s Tail The big dog wags its tail — after this. January 12, 2016

Featured Images

Hubble Space Telescope sequence of a supernova explosion

Cosmic Fireworks December 29, 2020

Multi-spectral view of Cassiopeia A, a supernova remnant

Brilliant Demise October 26, 2020

Supernova remnant N132D in the Large Magellanic Cloud

Breath of Life August 31, 2020

Vela Supernova Remnant

Big Bubble April 11, 2020

The constellation Orion

Land of the Supergiants January 4, 2020

Segment of Veil Nebula

Unveiling a Supernova August 30, 2019

composite image of a "cannonball" pulsar

Fire! April 5, 2019

Multiwavelength view of the Crab Nebula, M1

X-Raying a Crab January 7, 2019

Debris disk around a neutron star

Stellar Afterlife September 19, 2018

A combination of star-forming regions and the remains of an exploded star, seen in the infrared

Birth and Death August 3, 2018

Tycho's Supernova

Death Mask July 17, 2018

Combined optical, infrared view of the Crab Nebula

Colorful Crab April 19, 2018

X-ray view of Cassiopeia A

It's Elemental January 2, 2018

The Crescent Nebula

Colorful Demise December 14, 2017

pulsar schematic

Busy Corpse November 27, 2017

Combined X-ray and optical image of a supernova remnant

Zone of Death August 31, 2017

Multi-wavelength view of NGC 6946, the Fireworks Galaxy

Fireworks Factory August 23, 2017

Structure of a massive star shortly before it explodes as a supernova

Stellar Onion March 9, 2017

Composite image of Supernova 1987A

Brilliant Dead Star February 22, 2017

Cosmic ray shower

Cosmic Showers November 28, 2016

Hubble view of the Crab Nebula

Spectacular Crab December 14, 2015

Artist's concept of MY Camelopardalis, a contact binary star system

Close Twins March 15, 2015