A team of astronomers has made a remarkable discovery, unveiling an exoplanet with a lemon-like shape and an unprecedented atmosphere. The planet, named PSR J2322-2650b, was identified using the James Webb Space Telescope (JWST) and presents characteristics that challenge existing theories about planetary formation.
PSR J2322-2650b orbits a pulsar, a type of dead star, and has a mass comparable to that of Jupiter. Its unique ellipsoidal shape, reminiscent of a lemon or football, results from tidal forces exerted by the pulsar’s intense gravitational pull. This discovery adds to the growing list of exoplanets, but it stands out due to its strange properties.
Peter Gao, a member of the research team from the Carnegie Earth and Planets Laboratory, expressed his astonishment at the findings. “This was an absolute surprise,” Gao stated. “After we got the data down, our collective reaction was ‘What the heck is this?’ It’s extremely different from what we expected.”
The planet’s atmosphere is dominated by helium and carbon. According to the researchers, it likely contains clouds of carbon soot that can condense into diamonds, which may rain down on the planet’s surface. The proximity of PSR J2322-2650b to its pulsar is striking; it orbits just 1 million miles away, completing a rotation approximately every 8 hours. In comparison, Earth is about 100 million miles from the Sun.
New Insights into Planetary Atmospheres
The research team, led by Michael Zhang from the University of Chicago, noted the unusual composition of the planet’s atmosphere. “This is a new type of planet atmosphere that nobody has ever seen before,” Zhang explained. Instead of the molecules typically found on exoplanets, such as water or methane, the team detected molecular carbon, specifically C3 and C2.
The ability to observe PSR J2322-2650b illuminated by its host star without seeing the pulsar itself provides a “pristine spectrum” for analysis, according to Maya Beleznay, a graduate student involved in modeling the planet’s shape and orbit. “We can study this system in more detail than normal exoplanets,” she added.
The unique characteristics of this exoplanet have led researchers to classify it as part of a “black widow” system, a rare configuration where a rapidly spinning pulsar interacts with a small companion. In typical black widow systems, the pulsar gradually destroys its companion star through intense radiation. However, in this case, the companion is officially recognized as an exoplanet by the International Astronomical Union, distinct from a star.
Zhang remarked on the unusual formation of the planet, questioning whether it formed like a typical planet or through the stripping of a star’s exterior. “Did this thing form like a normal planet? No, because the composition is entirely different,” he said. “Nuclear physics does not make pure carbon.”
This discovery highlights the ongoing exploration of exoplanets and the complexities of planetary atmospheres in our universe. As researchers continue to analyze PSR J2322-2650b, they may uncover even more surprising details that challenge our understanding of planetary science.
