binarystar NASA

Stars are built with the lightest elements in the Universe, hydrogen and helium, but they contain an incomprehensible amount of mass. Our Sun is made of 2 x 10^30 kgs of stuff. That's a 2 followed by 30 zeros. That's 330,000 times more stuff than the Earth.


Rogue, or hypervelocity stars are moving so quickly they're leaving the Milky Way, and never coming back. They've got a one-way ticket to galactic voidsville. The velocity needed depends on the location, you'd need to be traveling close to 500 kilometers per second (about 1.1 million mph). That's more than twice the speed the Solar System is going as it orbits the centre of the Milky Way.



Because iron doesn't allow it to generate any energy, the star's gravity collapses it. In a fraction of a second, the star detonates, and anything nearby is incinerated. But what if you happen to be in a binary orbit with a star that suddenly vaporizes in a supernova explosion?

That companion star is flung outward with tremendous velocity, like it was fired from a sling, clocking up to 1,200 km/s. That's enough velocity to escape the pull of the Milky Way. Huzzah! Onward, to adventure! Ahh, crap… please do not be pointed at the Earth?

Another way to blast a star out of the Milky Way is by flying it too close to Sagitarrius A*, the supermassive black hole at the heart of the galaxy.

The European Southern Observatory
And for the bonus round, astronomers recently discovered stars rocketing away from the galactic core as fast as 900 km/s. It's believed that these travelers were actually part of a binary system.

Their partner was consumed by the Milky Way's supermassive black hole, and the other is whipped out of the galaxy in a gravitational jai halai scoop.



Considering the enormous mass of a star, it's pretty amazing that there are events so catastrophic they can kick entire stars right out of our own galaxy.


Check out the video on YouTube below: