Fastest star in the Milky Way, speed 8,226,967 km/h

Astronomers at the Harvard-Smithsonian Center for Astrophysics have discovered the fastest flying star ever seen in the Milky Way, setting a record at 8,226,967 km/h.

The white dwarf star J0927 blasted through space at incredible speed from a giant explosion. At this rate, it could one day completely escape the gravitational pull of the Milky Way. This super-fast star flies with 3 other fast-moving stars.

This super-fast-flying cluster is thought to be the result of a Type Ia supernova explosion. This is one of the most violent explosions in the universe that occurs when two stars (one of them a white dwarf) fall into orbits that revolve around each other. In this process, the white dwarf takes away hydrogen from the star it orbits, causing a reaction that leads to a massive thermonuclear explosion.

But that was not enough for the star to shoot out at a tremendous speed of 8,226,967 km/h. Astronomers suspect a special form of Type Ia supernova called supernova D6 is responsible for the supernova.

In supernova D6, when two white dwarfs orbit each other, one star will strip away the helium on the other's surface. This gives the white dwarf "cannibal" energy so great that it triggers a fusion reaction again, causing a shock wave to be sent deep into the core causing the star to explode.

There are many such powerful supernova explosions occurring in the universe but it is still very difficult to find evidence of them and white dwarfs being ejected. Astronomers have studied the Gaia star catalog, the project with the goal of creating the most detailed star map of the Milky Way and detecting white dwarfs. They also observed runaway white dwarfs as a result of explosions that caused them to lose helium and hydrogen.

Measurements show that J0927 has beaten the star D6-1, which once held the record at 7,919,904 km/h to become the fastest fleeing white dwarf ever observed in the Milky Way.

David Pac

Update 24 July 2023