NASA's Webb Captures A Hidden Planet That Fooled Astronomers For Years

by Aaron Leong — Thursday, July 16, 2026, 10:58 AM EDT

Astronomers have uncovered one of our cosmic neighborhood's most famous star systems, revealing a third planet that has evaded discovery for more than a decade. The newly-discovered world, Beta Pictoris d, resides 63 light-years away in the southern constellation of Pictor. Its discovery lifts Beta Pictoris to a rare status: it is now only the second planetary system known to host three or more directly imaged exoplanets.

Not that scientists were looking for it in the first place: this breakthrough was both an accidental discovery and a triumph of parallel science. Late last year, two independent research teams set out to study the young, 20-million-year-old star’s existing planetary family. A team led by astronomers at the University of Edinburgh and the European Southern Observatory (ESO) targeted the system using the Very Large Telescope (VLT) in Chile. Meanwhile, a California-led team pointed NASA’s James Webb Space Telescope (JWST) toward the same patch of sky. Neither group knew of the other’s ongoing work, deliberately avoiding contact to ensure they did not bias their respective results.

beta pictoris nirspec — *Webb's NIRSpec IFU was used to discover Beta Pictoris d. (Credit: NASA, ESA, CSA, STScI)*

Both campaigns were searching for something else entirely. While analyzing data from Webb, UCSD astronomer Aidan Gibbs and his team were investigating the previously known giant planet Beta Pictoris b. Instead of just seeing the target planet change over time, they noticed a weak, distinct spectral signal buried deep in the noise. By analyzing the chemical composition of methane, carbon monoxide, and water vapor, the Webb team identified the atmosphere of an entirely new, hidden planet.

Almost simultaneously, the ESO team under Markus Bonse spotted a tiny, faint point of light with the VLT's ERIS instrument. To verify the find, they combed through over 11 years of archival telescope data, realizing the planet had been hiding in plain sight, masked by the glare of the host star and its massive planetary siblings.

eso0842a — *Composite image of Beta Pictoris via infrared light using ESO's ADONIS instrument (Credit: ESO)*

That said, Beta Pictoris d is a relative lightweight compared to its neighbors. While Beta Pictoris b and c weigh in at roughly 8 to 13 times the mass of Jupiter, the newcomer is estimated to be about 2 to 4 times Jupiter's mass. This lower mass, combined with a relatively cool atmospheric temperature of roughly 330°C (626°F), makes it incredibly dim, i.e. about 100 times fainter than Beta Pictoris b, claiming the title of the faintest exoplanet ever directly imaged from Earth.

Beta Pictoris d orbits far out near the inner edge of the system's famous debris disk, taking roughly 91 years to complete a revolution around its parent star. Scientists believe the planet’s gravitational pull is actively carving and shaping the inner boundary of this massive ring.

Main image: Artist concept of the Beta Pictoris system with Beta Pictoris d at far right. (Credit: NASA, ESA, CSA, STScI)