Cosmic map: a thousand-colour image of the Sculptor Galaxy captured with the MUSE instrument at ESO’s Very Large Telescope (Courtesy: ESO/E. Congiu et al)

Astronomers at the European Southern Observatory’s Very Large Telescope (VLT) have created a thousand colour image of the nearby Sculptor Galaxy.

First discovered by Carloine Herschel in 1783 the spiral galaxy lies 11 million light-years away and is one of the brightest galaxies in the sky.

While conventional images contain only a handful of colours, this new map contains thousands, which helps astronomers to understand the age, composition and motion of the stars, gas and dust within it.

To create the image, researchers observed the galaxy for over 50 hours with the Multi Unit Spectroscopic Explorer (MUSE) instrument on the VLT, which is based at the Paranal Observatory in Chile’s Atacama Desert.

The team then stitched together over 100 exposures to cover an area of the galaxy about 65 000 light-years wide.

The image revealed around 500 planetary nebulae – regions of gas and dust cast off from dying Sun-like stars – that can be used as distance markers to their host galaxies. Read more World’s darkest skies threatened by industrial megaproject in Chile, astronomers warn

“Galaxies are incredibly complex systems that we are still struggling to understand,” notes astronomer Enrico Congiu, lead author of the study. “The Sculptor Galaxy is in a sweet spot – it is close enough that we can resolve its internal structure and study its building blocks with incredible detail, but at the same time, big enough that we can still see it as a whole system.”

Future work will involve understanding how gas flows, changes its composition, and forms stars in the galaxy. “How such small processes can have such a big impact on a galaxy whose entire size is thousands of times bigger is still a mystery,” adds Congiu.