Ben Sutlieff was not looking for a planet. In December 2025 the postdoctoral researcher at the University of Edinburgh simply wanted to measure the mid-infrared atmosphere of a long-known gas giant using the Very Large Telescope (VLT) of the European Southern Observatory in Chile. What he found in the data instead was a tiny speck – and with it the faintest exoplanet ever imaged directly from Earth.
Such specks are normally nothing. "When you see things like that, you work on the data some more, and these little scrappy signals go away because they're not real," Sutlieff told the magazine Scientific American. This one did not go away. Markus Bonse of ESO cleaned up the image using machine-learning algorithms – the dot stayed. "There's something else, did you see that?" Bonse recalls.
Overlooked for eleven years
The speck sat in the debris disk around the star Beta Pictoris, 63 light years away in the southern constellation Pictor. A background star could not be ruled out at first. Rather than wait years for fresh observations, the team searched the archives of ESO and the James Webb Space Telescope. The result: the planet had been visible there for eleven years – merely too faint to stand out. The trickiest material dated from 2014, when as seen from Earth it lay almost exactly in line with the far brighter Beta Pictoris b and was outshone by it.
Beta Pictoris d, as it is called, is about 100 times fainter than b and, at roughly 2.4 Jupiter masses, considerably lighter; its radius corresponds to 1.26 Jupiter radii. One orbit takes it around 90 years along a probably highly eccentric path that carries it up to 26 astronomical units from the star – for comparison, Uranus reaches just under 20, Neptune 30. At a good 320 degrees Celsius the gas giant is comparatively cool; that warmth still dates from its formation, when gas and dust contracted and gravitational energy was converted into heat. The more massive Beta Pictoris b runs to 1,500 degrees.
Why it matters: after HR 8799, Beta Pictoris is only the second system in which more than two planets have been directly imaged – and the newcomer also explains the striking shape of the debris disk around the star. Above all, the find shows that even well-studied systems can still be hiding planets. With ESO's future Extremely Large Telescope, more should follow. The team reports its work in the Astrophysical Journal Letters.