Astronomers have spotted a star orbiting the Milky Way's supermassive black hole at over 24,000 kilometers per second—roughly 8% the speed of light. And this cosmic speed demon is just the start.
Though the supermassive black hole at our galaxy's core is relatively calm compared to more active ones, its vicinity buzzes with intense activity. S-stars trace highly elliptical paths, daringly approaching the black hole before retreating to safety.
These stars allow astronomers to study the invisible giant they orbit. The standout is S2, which gets within less than 20 billion kilometers of the black hole.
Such close passes deliver powerful gravitational boosts, propelling S2 to about 3% the speed of light. Yet even faster stars circle this same behemoth.
Last year, a team led by astrophysicist Florian Peissker from Germany's University of Cologne highlighted S62. Over its 9.9-year orbit, it nears within less than 2.4 billion kilometers—closer than Uranus' average distance to the Sun. Speeds then exceed 20,000 km/s, or 6.7% light speed.
The team's latest finds include five more stars: S4711, S4712, S4713, S4714, and S4715.
S4714 steals the show. Every 12 years, it dives to about 1.9 billion kilometers from the black hole, hitting 24,000 km/s—8% light speed—before receding beyond 250 billion kilometers.
These stars qualify as "squeezars," a class first proposed in 2003 by astrophysicists Tal Alexander and Mark Morris.
They envisioned stars in highly eccentric orbits around massive black holes, offering insights into black hole growth and extreme tidal forces on stars.
Per Florian Peissker, S4711 and S4714 match those 2003 predictions perfectly.
This breakthrough not only reveals bolder stars around our galaxy's black hole but confirms the first real-world squeezars, nearly two decades after their theorization.
