James Webb Telescope Discovers Exotic Exoplanet with Diamond-Forming Interior

Scientists using NASA’s James Webb Space Telescope (JWST) have observed an unusual exoplanet whose atmospheric composition and origin defy existing planet-formation theories. The findings were published in The Astrophysical Journal Letters.

Key Findings

• The exoplanet, PSR J2322-2650b, is a Jupiter-mass object with an atmosphere dominated by helium and carbon, unlike any previously studied planet.
• Scientists infer the presence of soot-like carbon clouds, which may condense under extreme pressure deep inside the planet to form diamonds.
• Its chemical makeup challenges standard models of planetary formation, especially since it orbits a pulsar.

Why This Planet Is Unique

• Orbits a pulsar:
  PSR J2322-2650b circles a millisecond pulsar, a rapidly rotating neutron star that emits beams of electromagnetic radiation at precise intervals.
• Extreme proximity:
  The planet lies just 1 million miles from the pulsar (Earth is ~100 million miles from the Sun).
• Ultra-short year:
  One full orbit takes only 7.8 hours, among the shortest known planetary years.
• Distorted shape:
  Powerful tidal forces from the pulsar stretch the planet into a lemon-like shape.

Why JWST Could Study It So Well

• Pulsars emit mostly gamma rays and high-energy particles, which do not interfere with JWST’s infrared instruments.
• The absence of a bright host star allowed astronomers to observe the planet’s atmosphere clearly throughout its orbit.

About Pulsars and Neutron Stars

• Neutron stars form when massive stars exhaust their fuel and collapse, compressing protons and electrons into neutrons.
• They are the densest known objects—with the mass of the Sun packed into a city-sized sphere.
• Pulsars are rotating neutron stars with intense magnetic fields that emit radiation in lighthouse-like beams, observed as regular pulses.

Source: NASA