Galaxy's Fastest Star Was Ejected by Thermonuclear Supernova
Posted on March 9, 2015
6-27The fastest known star in the galaxy was ejected by a thermonuclear supernova. The star, US 708, is traveling at 1,200 kilometers per second or 2.7 million miles per hour. Astronomers say the speed of US 708 is so great that it will escape the gravity of our galaxy. The star is shown on the left with the supernova on the right in the above artist's impression.The star is known as an unbound star because it is not bound to our galaxy like our Sun is. It will eventually escape the gravity of the Milky Way and cruise around in intergalactic space.
The star was observed using the W. M. Keck Observatory and Pan-STARRS1 telescopes in Hawaii. The team of astronomers was led by Stephan Geier from the European Southern Observatory. The astronomers say the trajectory of US 708 indicates that the supermassive black hole at the center of the Milky Way is not the source of US 708's extreme speed. The astronomers theorize that US 708 once resided in an ultra compact binary system where helium was transferred to a massive white dwarf companion. This ultimately triggering a thermonuclear explosion of a type Ia supernova and US 708 was violently ejected.
This animation shows the white dwarf star accumulating matter and the supernova that ejected US 708. Take a look:
A research paper on the unbound star can be found here in the journal Science.
- Fossil of Giant Freshwater Turtle Discovered
- Hubble Observes Stormy Weather on Jupiter
- Australian Spider Named After Marvel's Venom
- NASA's JWST Captures New Views of NGC 604
- Ancient Giant Sea Lizard Had Dagger-Like Teeth