Merging white dwarf remnant (artist impression)

This image is an illustration of a merging white dwarf remnant. 

An international team of astronomers using the NASA/ESA Hubble Space Telescope have discovered a stellar rarity: an ultra-massive white dwarf that formed when a white dwarf merged with another star, rather than through the evolution of a single star. This discovery, which was made possible by Hubble’s sensitive ultraviolet observations, suggests that these rare white dwarfs may be more common than previously suspected.

[Image description: This illustration depicts a white dwarf star siphoning material off of a red giant star. The white dwarf has a long tail behind it and an orange shockwave in front of it as it flies through the extended atmosphere of the red giant, shown as a red glow. A broad stream of red gas is being pulled up from the red giant’s surface to the white dwarf.]