Betelgeuse, a red supergiant, was discovered to have been yellow 2,000 years ago.

Scientists have been able to roughly date when the supergiant star acquired its red colour by using historical representations

The scientists discovered that the star's hue shifted from yellow-orange to red some 2,000 years ago.

The star is located in the Milky Way's Orion constellation, about 640 light-years from Earth.

Betelgeuse is a red giant star, a type of stellar body that develops after completing the burning of hydrogen in its core

Long known to astronomers is the fact that stars' colours change over the course of their lives

These colour shifts, which are followed by brightness and size fluctuations

these can reveal important details about the age and mass of the star.