Produced by: Tarun Mishra Designed by: Manoj Kumar
Located 1,200 light-years from Earth, WASP-193b stands out as an anomaly among over five thousand known exoplanets. It is 50% larger than Jupiter but seven times less massive, resulting in an extremely low density similar to cotton candy.
Khalid Barkaoui, a postdoctoral researcher at ULiege’s EXOTIC Laboratory, explains that WASP-193b is the second least dense planet discovered, only surpassed by Kepler-51d, which is significantly smaller.
The planet’s low density defies standard models of irradiated gas giants, even under the unrealistic assumption that it has no core. Barkaoui emphasizes that WASP-193b is a true anomaly among discovered exoplanets.
The planet was first spotted by the Wide-Angle Search for Planets (WASP), an international collaboration using robotic observatories to monitor the brightness of thousands of stars. Periodic dips in the light from WASP-193 suggested a transiting planet.
The planetary nature of WASP-193b was validated using the TRAPPIST-South and SPECULOOS-South observatories in Chile. Spectroscopic observations from HARPS and CORALIE spectrographs measured the planet’s mass.
The collected data revealed WASP-193b’s extremely low density, with a mass and size about 0.14 and 1.5 times that of Jupiter, respectively. This results in a density of approximately 0.059 grams per cubic centimeter, akin to cotton candy.
Julien de Wit, a professor at MIT and co-author of the study, describes the planet as “super fluffy,” noting its difficulty in finding a solid-state material with a comparable lightness.
Researchers believe WASP-193b is mostly composed of hydrogen and helium, with an atmosphere extending tens of thousands of kilometers beyond Jupiter’s. Current planetary formation theories cannot explain the planet’s extreme inflation.
As astronomers continue to study WASP-193b’s atmospheric properties using instruments like the James Webb Space Telescope, this discovery may provide new insights into the evolutionary paths of similarly extreme and inflated planets.