Out of this world! Scientists snap most detailed image of galaxy yet

As far as galactic pictures go, this one’s a masterpiece.

Astronomers have created an ultra-detailed image of the Sculptor Galaxy, covering an area around 65,000 light-years wide.

Using the European Southern Observatory’s Very Large Telescope, they captured more than 100 exposures detailing thousands of colours.

And the result is this stunning composite of pink and blue hues that provide a snapshot of the lives of stars within it.

The Sculptor Galaxy, which is one of the brightest visible in the night sky, is located 11 million light-years away.

It is a spiral galaxy that can be seen in the Southern Hemisphere sky and is so bright because it’s what’s known as a ‘starburst galaxy’, meaning it is undergoing very high rates of star formation.

To create this new map, researchers observed the galaxy for over 50 hours. They then stitched together more than 100 exposures to cover an area of the galaxy around 65,000 light-years wide.

According to co-author Kathryn Kreckel from Heidelberg University in Germany, this makes the map a potent tool.

‘We can zoom in to study individual regions where stars form at nearly the scale of individual stars, but we can also zoom out to study the galaxy as a whole,’ she said.

In their first analysis of the data, the team uncovered around 500 planetary nebulae – regions of gas and dust cast off from dying Sun-like stars.

Co-author Fabian Scheuermann, a doctoral student at Heidelberg University, said: ‘Beyond our galactic neighbourhood, we usually deal with fewer than 100 detections per galaxy.’

Because of the properties of planetary nebulae, they can be used as distance markers to their host galaxies. 

‘Finding the planetary nebulae allows us to verify the distance to the galaxy — a critical piece of information on which the rest of the studies of the galaxy depend,’ said Adam Leroy, a professor at The Ohio State University, USA, and study co-author.

Since a galaxy’s building blocks – stars, gas and dust – emit light at different colours, the more shades of colour there are in an image the more researchers can learn about its inner workings.

And as this map comprises thousands of colours, astronomers can work out the age, composition and motion of the stars, gas and dust within.

‘Galaxies are incredibly complex systems that we are still struggling to understand,’ researcher Dr Enrico Congiu, who led the study, said.

‘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 projects using the map will explore how gas flows, changes its composition, and forms stars all across this 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,’ Dr Congiu added.

This research was presented in a paper accepted for publication in Astronomy & Astrophysics.

THE VERY LARGE TELESCOPE IS A POWERFUL GROUND-BASED INSTRUMENT IN CHILE

The European Southern Observatory (ESO) built the most powerful telescope ever made in the Atacama Desert of northern Chile.

It is called the Very Large Telescope (VLT) and is widely regarded as one of the most advanced optical instruments ever made.

It consists of four telescopes, whose main mirrors measures 27 feet (8.2 metres) in diameter.

There are also four movable six feet (1.8 metre) diameter auxiliary telescopes.

The large telescopes are called Antu, Kueyen, Melipal and Yepun. 

The first of the Unit Telescopes, ‘Antu’, went into routine scientific operations on April 1, 1999.

The telescopes can work together to form a giant ‘interferometer’.

This interferometer allows images to be filtered for any unnecessary obscuring objects and, as a result, astronomers can see details up to 25 times finer than with the individual telescopes.  

It has been involved in spotting the first image of an extrasolar planet as well as tracking individual stars moving around the supermassive black hole at the centre of the Milky Way.

It also observed the afterglow of the furthest known Gamma Ray Burst.