In a groundbreaking discovery, scientists have identified a peculiar lemon-shaped exoplanet named PSR J2322-2650b. Found using NASA’s James Webb Space Telescope, this exoplanet challenges established theories about planet formation and atmospheric composition. The study, published in The Astrophysical Journal Letters, highlights how PSR J2322-2650b exhibits characteristics that differ significantly from known exoplanets orbiting main-sequence stars.
Unique Characteristics of PSR J2322-2650b
PSR J2322-2650b possesses a mass comparable to that of Jupiter but orbits a pulsar, which is a rapidly spinning neutron star. This pulsar emits beams of electromagnetic radiation at regular intervals, resembling a lighthouse, and serves as a remnant of a star that has undergone a supernova explosion. The planet orbits its pulsar at an astonishing distance of just 1 million miles, significantly closer than Earth’s distance from the Sun, which is approximately 100 million miles. As a result of this tight orbit, PSR J2322-2650b completes a full revolution around its pulsar in merely 7.8 hours.
The gravitational forces exerted by the pulsar contribute to the planet’s unusual shape. According to Scientific American, the planet’s proximity to its host star is causing it to take on a lemon-like form.
Scientists are particularly intrigued by the planet’s atmosphere, which appears to be unlike any previously observed. Michael Zhang, a postdoctoral researcher at the University of Chicago and coauthor of the study, noted, “Instead of finding the normal molecules we expect to see on an exoplanet — like water, methane, and carbon dioxide — we saw molecular carbon, specifically C3 and C2.” The atmosphere is reported to be dominated by helium and carbon, and it may contain clouds of carbon soot that could condense to form diamonds raining down onto the planet.
The Formation Mystery
The unusual characteristics of PSR J2322-2650b prompt significant questions about its formation. While it is classified as an exoplanet, some researchers theorize that it may be the stripped remains of a former star due to its unique composition. This hypothesis raises further questions about the absence of oxygen and nitrogen in the planet’s atmosphere.
NASA describes the star-planet combination as a “black widow system,” a rare type of double system where a rapidly spinning pulsar interacts with a small, low-mass stellar companion. In such systems, the pulsar can erode and consume the companion through jets of radiation. If PSR J2322-2650b is indeed part of a black widow system, it may be on the edge of being completely consumed by its pulsar. As noted by The New York Times, we may be witnessing the “very last moments” of this exoplanet.
Zhang elaborated on the planet’s formation, stating, “Did this thing form like a normal planet? No, because the composition is entirely different. Did it form by stripping the outside of a star, like ‘normal’ black widow systems are formed? Probably not, because nuclear physics does not make pure carbon.”
The discovery of PSR J2322-2650b not only adds a new chapter to the study of exoplanets but also raises profound questions about the processes that govern planetary formation in extreme environments. As researchers continue to analyze this enigmatic world, the implications for our understanding of the universe are both exciting and far-reaching.