An international team of researchers from the EXOTIC Laboratory of the University of Liège, MIT, and the Astrophysics Institute in Andalusia has recently discovered WASP-193b, an extremely low-density giant planet orbiting a distant Sun-like star. This new planet, located 1,200 light-years from Earth, is 50% larger than Jupiter but seven times less massive, giving it a density comparable to that of cotton candy. Its unique characteristics make it an anomaly among the over five thousand exoplanets discovered so far, as standard models cannot reproduce its density.
The planet was first identified by the Wide Angle Search for Planets (WASP) project, which used two robotic observatories in the northern and southern hemispheres to detect periodic transits of the star WASP-193. The observatories measured the amount of light blocked by the planet during each transit, providing an estimate of its size. Further observations from the TRAPPIST-South and SPECULOOS-South observatories in Chile confirmed the planetary nature of the object, while spectroscopic data from the HARPS and CORALIE spectrographs revealed its mass. The resulting calculations showed an incredibly low density for the planet, which is about 0.059 grams per cubic centimeter.
The researchers believe that WASP-193b is primarily composed of hydrogen and helium, similar to many other gas giants in the galaxy. These gases likely form an inflated atmosphere that extends far beyond Jupiter’s atmosphere. The exact mechanism behind the planet’s extreme inflation remains a mystery, as it does not align with current theories of planetary formation. Further study of the planet’s atmosphere could help shed light on its evolutionary path and provide insights into how it was formed. The researchers are planning to use the JWST space telescope to measure its atmospheric properties and explore different theoretical mechanisms that may explain its unusual characteristics.
The team’s findings challenge existing models of planetary formation and highlight the need for more observational and theoretical work to understand WASP-193b. Its discovery opens up new avenues for studying extreme exoplanets and expanding our understanding of the diversity of planets beyond our solar system. Further research into the planet’s composition and atmospheric properties could provide valuable insights into the processes that shape planetary systems and help solve the mystery of this cosmic enigma.
