Home Front Page Stellar explosion blasts star through Milky Way at incredible speed

Stellar explosion blasts star through Milky Way at incredible speed

A star deep in our galaxy is moving at a blistering pace — 1,200 kilometers per second, a speed record, a team of scientists has discovered.

Astronomers at the University of Hawaii at Mano used some powerful telescopes to track the star, which is moving so fast that it will escape our Milky Way galaxy, according to a Space Daily report.

A thermonuclear supernova explosion blasted the star into space, according to the study, which was published in the journal Science.

Typically, the gravity from a galaxy is so strong that stars can’t escape, as they are moving at fairly moderate speeds, typically between tens and hundreds of kilometers per second. Usually, coming close to the supermassive black hole at the center of the Milky Way is responsible for boosting a star’s speed enough that it would be able to escape the galaxy.

The star, US 708, was observed by a team led by Stephan Geier of the European Southern Observatory in Germany. They combined position measurements from digital archives with some of the newer positions that had been measured in a survey, and using that they were able to figure out just how fast the star is moving.

They finally pegged the speed at 1,200 kilometers per second, or 2.7 million miles per hour. That’s a lot faster than any other stars in our galaxy, and the trajectory indicates that the supermassive black hole is not the cause of its high speed.

What does it mean? US 708 was probably part of an ultracompact binary system that transferred helium to a huge white dwarf companion, causing a tremendous thermonuclear explosion that ejected US 708 from the disrupted binary out into space.

The star is rotating very rapidly and is made of helium, a remnant of massive star that lost its envelope of hydrogen.

The discovery suggests a link between helium-based stars and thermonuclear supernovae, which could help scientists better understand such massive and yet mysterious explosions.