Technology & Science
JWST Spots Carbon-Helium ‘Space Lemon’ Orbiting a Pulsar
On 16 Dec 2025, Webb spectroscopy exposed PSR J2322-2650b—a Jupiter-mass body circling a millisecond pulsar—as the first known world with a helium-and-molecular-carbon atmosphere and a 38 % tidal stretch, overturning existing planet-formation models.
Focusing Facts
- The object orbits just 1 million mi / 1.6 million km from its pulsar and completes a full orbit in 7.8 hours.
- Peer-reviewed JWST spectra (1–5 µm) revealed dominant C2 and C3 signatures with near-zero oxygen or nitrogen—unique among the ~150 exoplanet atmospheres catalogued to date.
- Phase-curve photometry indicates its equatorial diameter is ~38 % wider than its polar diameter, the largest confirmed exoplanet distortion.
Context
Astronomers last saw planets around pulsars in 1992 (PSR B1257+12), but those Earth-mass worlds showed conventional compositions; PSR J2322-2650b’s carbon-helium shroud echoes the 2011 ‘diamond planet’ PSR J1719-1438 b yet pushes the anomaly farther by retaining Jupiter mass and active atmosphere. The find sits at the crossroads of two long arcs: telescopic sensitivity—from Hubble’s first exoplanet transits in 1999 to JWST’s infrared spectra—shifts discovery from mere detection to chemical forensics, and theorists must now accommodate planetary survival in extreme post-supernova environments. If pulsar-orbiting gas giants with exotic chemistries exist, the canonical star-disk accretion narrative (a 4.6-billion-year-old idea tracing to Laplace) is incomplete. On a century horizon, such outliers may refine models of matter segregation, nucleosynthesis remnants, and even diamond formation physics, or they may remain statistical curiosities reminding us that sample bias—not nature—limits theory.
Perspectives
NASA official communications and NASA-aligned science coverage
Science@NASA, Space.com — The Webb observations unveil a previously unknown type of exoplanet whose helium-and-carbon atmosphere proves the space telescope’s unrivaled power and pushes planet-formation theory into new territory. By centering NASA’s instrument and adopting the IAU exoplanet definition, the reports subtly promote agency achievements and downplay the ongoing debate over whether the object is actually a stripped stellar core rather than a bona-fide planet.
Digital popular-science outlets that trade on eye-catching mystery
IFLScience, Mashable, Yahoo reprints — Writers revel in the discovery’s "what the heck" weirdness, depicting a crimson, diamond-raining, lemon-shaped world that overturns everything we thought we knew about planets and fuels sci-fi dreams. Heavy use of hyperbole and repetition of colourful quotes is designed to maximise clicks, sometimes glossing over technical caveats and giving readers more spectacle than scientific nuance.
Tabloid and general-news sites that sensationalize or question its planetary status
The Financial Express, Daily Mail, Oddee — The object is portrayed as the “stretchiest world” that may not even be a planet at all but the stripped remains of a star doomed to be eaten, underscoring how it ‘defies explanation’. To attract broad audiences these outlets amplify the most dramatic angle—doubting the planet label, stressing bafflement, and inserting pop-culture jokes—sometimes conflating speculation with consensus science.