science & techESA/Hubble

A white dwarf's explosion leaves a tangled web that helps measure the universe

the gist

SNR 0454-67.2 is the expanding debris of a supernova in the Large Magellanic Cloud, a satellite galaxy of the Milky Way. It is most likely a Type Ia supernova, which happens when a white dwarf star pulls material from a companion until it reaches a critical mass and explodes. Because these explosions occur at the same mass, they release about the same amount of light, so they work as standard candles. Astronomers compare how bright they look with how bright they should be to measure distances. The red threads in this image are material flung outward by the blast.

so what

Type Ia supernovae were central to the discovery that the expansion of the universe is accelerating, which earned a Nobel Prize in 2011. Their predictable brightness makes them one of cosmology's most important distance tools.

ESA/Hubble · CC BY 4.0

Image: ESA/Hubble, NASA