Researchers have unveiled the highest-ever resolution images of the sun.

The images, analysed by researchers at the University of Central Lancashire (UCLan) and collaborators from NASA's Marshall Space Flight Centre, provide astronomers with a better understanding of the sun's complex atmosphere.

Until now, certain parts of the sun's atmosphere had appeared dark or mostly empty.

However, the new images have revealed it actually contains strands of hot electrified gases that are around 500km (311 miles) in width.

The ultra-sharp images were taken by NASA's High-Resolution Coronal Imager (Hi-C) telescope, carried into space on a sub-orbital rocket flight.

The telescope can pick out structures in the sun's atmosphere as small as 70km in size, or about 0.01% of its total size.

Although what exactly is creating these strands remains unclear, scientific debate will now focus on why they are formed and how their presence helps us understand the eruption of solar flares and solar storms that could affect life on Earth.

Robert Walsh, professor of solar physics at UCLan, said the images provided an "ultra-high definition" glimpse of the sun for the first time.

"Until now, solar astronomers have effectively been viewing our closest star in 'standard definition', whereas the exceptional quality of the data provided by the Hi-C telescope allows us to survey a patch of the sun in 'ultra-high definition' for the first time," he said.

Tom Williams, a postdoctoral researcher at UCLan who worked on the Hi-C data, said the images would help provide a greater understanding of how the Earth and sun related to each other.

"This is a fascinating discovery that could better inform our understanding of the flow of energy through the layers of the sun and eventually down to Earth itself," he said.

"This is so important if we are to model and predict the behaviour of our life-giving star."