When astronomers want to see the finest details, they typically face a fundamental limitation, the size of their telescope. Bigger telescopes capture more light but also reveal a finer level of detail and so produce sharper images. This is why astronomers often link multiple telescopes together to create arrays spanning kilometres employing a technique known as interferometry. However, a UCLA led team has just demonstrated a clever workaround that achieves what some claim to be record breaking resolution using a single telescope and a device that sounds like it belongs in a fantasy novel, a photonic lantern.

The photonic lantern is a specially designed optical fibre that does something rather extraordinary with starlight. Instead of treating light as a simple beam, it splits the incoming light according to its spatial patterns, much like separating a musical chord into its individual notes. These subtle patterns, which contain information about the structure of distant objects, are normally lost in traditional imaging techniques. By preserving and analysing them, the team have shown that it’s possible to reconstruct images with far greater detail than should theoretically be possible from a telescope of that size.

The team put this technique to the test at the Subaru Telescope in Hawaii and focussed it on a star called Beta Canis Minoris, located about 162 light years away in the constellation Canis Minor. This star is surrounded by a rotating disc of hydrogen gas, and the researchers wanted to use their new device to study its structure in unprecedented detail. What they discovered surprised them, the disc isn't perfectly symmetrical but appears rather more lopsided, a feature that wasn't visible with conventional imaging methods.