Speed stars, or hypervelocity stars, are stars that speed stars travel at speeds far exceeding the typical motion of stars within a galaxy. For example, the star US 708, discovered in 1982, moves at 1,200 km/s (2.7 million mph), one of the fastest recorded in the Milky Way. These stars achieve such velocities through dramatic cosmic events:
Black Hole Slingshots: A binary star system passing close to a supermassive black hole, like Sagittarius A* at the Milky Way’s center, can be disrupted. One star may be ejected at high speed, reaching up to 1,000–2,400 km/s.
Supernova Kicks: In a binary system, a supernova explosion of one star can propel its companion at extreme velocities, as seen with some white dwarfs moving at 2,400 km/s.
Galactic Interactions: Stars from dwarf galaxies, like the Large Magellanic Cloud, can be flung into the Milky Way at high speeds due to gravitational interactions.
These natural phenomena inspire scientists to consider how artificial propulsion systems might mimic such speeds for interstellar travel.