2025-12-16 シカゴ大学
A strange planet (left) orbits a rapidly spinning neutron star called a pulsar (right). This artist’s illustration shows that gravitational forces from the much heavier pulsar are pulling the world into the shape of a lemon. This planet, studied with NASA’s James Webb Space Telescope, appears to have an exotic atmosphere unlike any ever seen before.Image courtesy of NASA, ESA, CSA, Ralf Crawford (STScI)
＜関連情報＞
- https://news.uchicago.edu/story/nasas-webb-telescope-finds-bizarre-atmosphere-lemon-shaped-exoplanet
- https://arxiv.org/abs/2509.04558
風の強いパルサー惑星の炭素に富んだ大気 A carbon-rich atmosphere on a windy pulsar planet
Michael Zhang, Maya Beleznay, Timothy D. Brandt, Roger W. Romani, Peter Gao, Hayley Beltz, Matthew Bailes, Matthew C. Nixon, Jacob L. Bean, Thaddeus D. Komacek, Brandon P. Coy, Guangwei Fu, Rafael Luque, Daniel J. Reardon, Emma Carli, Ryan M. Shannon, Jonathan J. Fortney, Anjali A.A. Piette, M. Coleman Miller, Jean-Michel Desert
arXiv last revised 15 Dec 2025 (this version, v2)
DOI:https://doi.org/10.48550/arXiv.2509.04558
Abstract
A handful of enigmatic Jupiter-mass objects have been discovered orbiting pulsars. One such object, PSR\,J2322-2650b, uniquely resembles a hot Jupiter exoplanet due to its minimum density of 1.8 g/cm^3 and its ~1900 K equilibrium temperature. We use JWST to observe PSR J2322-2650b’s emission spectrum across an entire orbit. In stark contrast to every known exoplanet orbiting a main-sequence star, we find an atmosphere rich in molecular carbon (C3, C2) with strong westward winds. Our observations open up new exoplanetary chemical (ultra-high C/O and C/N ratios of >100 and >10,000, respectively) and dynamical regimes (ultra-fast rotation with external irradiation) to observational study. The extreme carbon enrichment poses a severe challenge to the current understanding of “black widow” companions, which were expected to consist of a wider range of elements due to their origins as stripped stellar cores.
