An exoplanet with a distinct shape is challenging many of the previously held assumptions about planetary formation. PSR J2322-2650b, which has a mass similar to Jupiter and was found using Nasa ’s James Webb telescope, has properties that are in “stark contrast to every known exoplanet orbiting a main-sequence star”, according to a study published in The Astrophysical Journal Letters.
“The planet orbits a star that's completely bizarre – the mass of the sun, but the size of a city,” said study co-author Michael Zhang. PSR J2322-2650b is also unusually close to its star – a full orbit takes only 7.8 hours – and that proximity means “the star’s gravity is pulling the planet into a lemon shape”, said Scientific American.
What has interested scientists most is the planet’s atmosphere, which is “dominated by helium and carbon, and likely has clouds of carbon soot that condense to create diamonds that rain down onto the planet”, said Space.com. “Everywhere in the universe, where there’s carbon, there tends to be nitrogen and oxygen,” Zhang told Scientific American.
PSR J2322-2650b and its star together form a “black widow system,” which is a “rare type of double system where a rapidly spinning pulsar [the star] is paired with a small, low-mass stellar companion”, said Nasa. Over time, the pulsar “erodes and devours” the formation in its orbit with “jets of radiation”, said Space.com. If that’s the case, we may have witnessed the “very last moments”, with PSR J2322-2650b “on the cusp of being entirely consumed”, said The New York Times.
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