Overview
- Phase-resolved Webb spectra show an atmosphere dominated by helium and molecular carbon chains (C2, C3), with oxygen and nitrogen largely absent.
- The companion, roughly Jupiter-mass, circles its millisecond pulsar at about 1 million miles every 7.8–8 hours, is tidally locked, and is stretched into a pronounced lemon-like shape.
- Element ratios are extreme, with carbon-to-oxygen exceeding 100:1 and carbon-to-nitrogen above 10,000:1, unlike any characterized planetary atmosphere.
- Temperatures swing from about 3,700°F on the dayside to roughly 1,200°F on the nightside, with heat patterns shifted westward relative to standard hot-Jupiter expectations.
- Because the host emits mostly gamma rays, JWST’s infrared instruments isolated the companion’s signal, enabling detailed atmospheric measurements published December 16 in The Astrophysical Journal Letters.