The school has linked up with the Faulkes Telescope Project, an organisation in Cardiff that has telescopes in Hawaii and Australia. Pupils can study the stars during daylight as night falls on the other side of the world.
Ros Houmoller, Gwernyfed's head of art, was so impressed with the picture quality that she decided to take the project out of the science lab. "You can see galaxies," she said. "I'm not an expert but they look stunningly beautiful."
After displaying the photographs, pupils in the after-school art club produced their own art based on the images.
Mrs Houmoller said: "Their artwork is very much an emotional response to the photos, although they do actually look like galaxies.
"The children were completely carried away, using paint and throwing swirls around."
The artwork will be displayed at the Glasbury arts festival at Hay-on-Wye during November.