Astronomers have identified a planet that challenges existing theories of planet formation. The newly discovered planet, designated PSR J2322-2650b, is roughly the size of Jupiter but takes on a distorted, lemon-like shape due to intense gravitational forces. It orbits a pulsar, the ultra-dense remnant of a dead star, completing a full orbit every 7.8 hours. The extreme proximity to its host pulsar exposes the planet to high-energy radiation, leading to atmospheric temperatures that reach approximately 3,700 degrees Fahrenheit on the dayside, while the nightside cools to around 1,200 degrees.
Unprecedented Discoveries in Planetary Atmosphere
Using the James Webb Space Telescope, scientists monitored PSR J2322-2650b throughout its entire orbit. They aimed to analyze how light passed through the planet’s atmosphere, but the findings were unexpected. Instead of the usual combination of hydrogen, oxygen, and nitrogen found in gas giants, researchers detected a spectrum dominated by carbon-based molecules. Specific signals from carbon chains known as C2 and C3 were prominent, while oxygen and nitrogen were either scarce or entirely absent.
Michael Zhang, the lead author of the study, remarked on the unusual nature of the planet: “The planet orbits a star that’s completely bizarre—the mass of the Sun, but the size of a city. This is a new type of planet atmosphere that nobody has ever seen before.”
The findings reveal an extreme carbon-to-oxygen ratio exceeding 100 to one, and a carbon-to-nitrogen ratio surpassing 10,000 to one. Such ratios have no parallel in known planets orbiting normal stars, and the current models explaining planet formation around pulsars do not account for these anomalies.
Rethinking Planetary Formation Theories
Typically, systems like this are categorized as “black widows,” where a pulsar gradually strips material from a companion star, potentially leaving behind a dense remnant. This process should yield a diverse mix of elements rather than an atmosphere heavily dominated by carbon. The research team considered various explanations, including unusual stellar chemistry or the influence of carbon-rich dust, but none fully explained the observations made by the James Webb Space Telescope.
Additionally, the heating patterns on PSR J2322-2650b differ from those typically seen in hot Jupiters. Gamma rays penetrate more deeply into the atmosphere, creating wind patterns that shift heat westward instead of directly away from the pulsar. Consequently, the hottest region on the planet does not align with traditional models.
For now, PSR J2322-2650b remains an enigma. The James Webb Space Telescope has confirmed its unique characteristics, but the mystery of how this unusual planet came to be continues to perplex scientists. As researchers delve deeper into the complexities of planetary formation, discoveries like this one highlight the need to refine our understanding of the universe’s diverse phenomena.
