WASP-193b, a fascinating exoplanet located 1,200 light-years away from Earth, is causing quite a stir among astronomers. This newly discovered planet is a true anomaly in the realm of exoplanets, boasting a density akin to that of cotton candy. Despite being 50% larger than Jupiter, WASP-193b is seven times less dense, making it the second least dense planet ever discovered, after Kepler-51d.
The groundbreaking study detailing the findings of WASP-193b was led by Khalid Barkaoui, a postdoctoral researcher at ULiege's EXOTIC Laboratory. Published in Nature Astronomy, the study sheds light on the perplexing nature of this enigmatic planet. Barkaoui notes, "Its extremely low density makes it a real anomaly among the more than five thousand exoplanets discovered to date.
" The discovery of WASP-193b was made possible by the Wide Angle Search for Planets (WASP) project, an international effort utilizing two robotic observatories to survey hundreds of stars in the night sky. The distinct signal of a transiting planet was identified through periodic dimming of the star WASP-193, prompting further investigation. To confirm the planetary nature of the eclipsing object, observations were carried out using the Chilean observatories TRAPPIST-South and SPECULOOS-South.
Spectroscopic measurements conducted with the CORALIE and HARPS spectrographs in Chile enabled researchers to determine the planet's mass and size, revealing values comparable to 0.14 times and 1.5 times that of Jupiter, respectively.
The most striking aspect of WASP-193b, however, lies in its exceptionally low density of 0.059 grams per cubic centimeter. This figure, akin to the density of cotton candy, highlights the planet's unique composition and structure.
Co-author and MIT professor Julien de Wit emphasizes, "The planet is so light that it's difficult to think of an analogous, solid-state material. The planet is basically super fluffy." Researchers believe that WASP-193b is predominantly composed of hydrogen and helium, with an inflated atmosphere stretching tens of thousands of kilometers beyond Jupiter's atmosphere.
Despite these insights, the mechanism underlying the planet's massive expansion remains a baffling mystery. Francisco Pozuelos, an astronomer at the Instituto de Astrofisica de Andalucia, admits, "We cannot explain how this planet was formed. We don't know where to put this planet in all the formation theories we have right now, because it's an outlier of all of them."
The discovery of WASP-193b underscores the potential for further exploration and discovery in the realm of exoplanets. Its unconventional characteristics challenge existing models of planetary formation and invite further research to unravel the mysteries of this distant world. As scientists continue to push the boundaries of our understanding of the universe, discoveries like WASP-193b serve as reminders of the boundless wonders that await us beyond our own celestial neighborhood.
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