Something is amiss in the Butterfly Nebula. When astronomers compared two exposures of this planetary nebula that had been taken by the Hubble Space Telescope in 2009 and 2020, they saw dramatic ...

When a star runs out of fuel, it sheds its outer layers of gas and, if it doesn't explode in a supernova, forms a glowing shell of ionized gas that expands into space. Shells like these are known as ...

A color rendition of NGC 6302, the Butterfly Nebula, created from black-and-white exposures taken by the Hubble Space Telescope in 2019 and 2020. In the violet-colored regions, strong stellar winds ...

Planetary nebulae form when red giant stars expel their outermost layers as they run out of helium fuel — becoming hot, dense white dwarf stars that are roughly the size of Earth. The material that ...