WASHINGTON: The Tabby's Star - the most mysterious star in the universe - dims and brightens in an unusual manner due to dust particles, say scientists who have debunked the theory that the cosmic body is being orbited by an Alien Megastructure.

The new data shows that different colours of light are being blocked at different intensities," said Tabetha Boyajian, professor at the Louisiana State University in the US.

The last two were named after ancient lost cities - Scotland's Scara Brae and Cambodia 's Angkor.

In many ways what is happening with the star is like these lost cities, researchers wrote in the study published The Astrophysical Journal Letters.

Citizen scientists, the Planet Hunters, sifting through massive amounts of data from the NASA Kepler mission were the ones to detect the star's unusual behaviour in the first place.