Moving at a speed of more than 54,000 mph (24 km per second) relative to their surroundings, runaway stars can be a spectacle for anybody to watch in the night sky. A special type of star, they move alone and the nature of their “bow shock” can reveal some information about their origin. These bow waves lend the speedy stars a significant signpost, which enables their spotting.

A scientist likened the star’s movement to a boat cruising through the ocean and the bow of the vessel being pushed against water flowing in the opposite direction. The resulting wave, known as a "bow wave", is somewhat similar to the manner in which these speedsters travel, the phenomenon called “bow shocks”.

The scientists have so far studied about one-third of the Milky Way's length and turned up more than 200 candidate "bow shocks".

William Chick, a PhD student at the University of Wyoming, said, "We took a look at our arc-shaped objects and tried to find stars present in the centre of each image… We were surprised to discover that over 95% of these stars were in fact hot massive stars, as we'd predicted”.

The scientists based their study on survey images taken by Wise and Spitzer, two infra-red telescopes launched into orbit in the 2000s. The findings were presented at the 227th conference of the American Astronomical Society in Florida.

The findings showed that these stars originate after being flung from their home neighbourhood by the medium of gravity or stellar explosions. As runaways move, material piles up ahead of them, gets warmed up and shines.

Researchers have combed the galaxy for the curved waves of material that runaway stars plough before them and have identified dozens of the stars in the Milky Way.

Though not much is known about these runaways, infra-red surveys by Wise and Spitzer telescopes have enabled the scientists to identify the speedsters across the sky.