James Webb Discovers Lemon-Shaped Exoplanet Near Pulsar

The James Webb Space Telescope has revealed one of the most extreme and unusual worlds ever detected beyond the Solar System. Located about 2,000 light-years from Earth, the exoplanet PSR J2322-2650b displays a striking lemon-like shape, challenging long-held assumptions about planetary structure and survival in hostile cosmic environments.

An extreme planet in a hostile orbit

PSR J2322-2650b orbits a millisecond pulsar, the ultra-dense remnant of a collapsed star. Unlike typical planets that circle luminous stars, this world revolves around an object roughly the mass of the Sun but compressed to the size of a city. The planet completes one orbit in just 7.8 hours at a distance of nearly one million miles, exposing it to intense gravity and relentless radiation.

Record-breaking temperatures and tidal stress

The close orbit subjects the Jupiter-sized planet to extreme heating. Observations indicate temperatures of about 3,700°F on the side facing the pulsar, while the far side remains near 1,200°F. These enormous temperature differences and gravitational forces stretch the planet along its orbit, producing its distinctive lemon-like appearance through powerful tidal deformation.

A chemically unique atmosphere

Using advanced infrared instruments, Webb captured a detailed atmospheric profile unlike any previously recorded. Instead of common molecules such as water vapour or methane, PSR J2322-2650b shows abundant carbon compounds, including C₂ and C₃, along with helium. The near absence of oxygen and nitrogen marks it as chemically distinct from over 150 exoplanets studied so far.

What to Note for Exams?

• PSR J2322-2650b orbits a millisecond pulsar, not a main-sequence star.
• The planet completes one orbit in approximately 7.8 hours.
• Its atmosphere is dominated by carbon compounds and helium.
• Tidal forces stretch the planet into a non-spherical, lemon-like shape.

Carbon clouds and unanswered questions

Webb data suggest the presence of carbon-rich soot clouds, with interior conditions potentially allowing carbon to crystallise under extreme pressure. Existing models of planetary formation struggle to explain such a chemically pure carbon environment. As a result, PSR J2322-2650b stands as a key example of how Webb continues to expose gaps in current theories about how planets form and endure in the most extreme regions of the universe.