What WASP-69b’s Comet-Like Tail Tells Us About Hot Exoplanets

WASP-69b is a gas giant exoplanet with a diameter slightly larger than Jupiter but a mass less than a third of Jupiter. It is often referred to as a “hot Jupiter” because of its compositional similarities to the gas giant and proximity to its host star. WASP-69b is located a mere 0.04525 AU from its star, making its orbit only 3.9 days long. This closeness is what allows the exoplanet to be around the same size as Jupiter, despite only being 0.29 Jupiter masses. The heat from its host star gives more energy to the gases the planet is comprised of, allowing it to expand. Because the gases that makeup WASP-69b’s atmosphere are not as compressed as the gas giants in our solar system, material from its atmosphere can escape much more easily. Previous observations of the planet suggested that it is losing some atmosphere and may have a small tail of helium gas leaving the planet as it rotates. Now, new research published in January finds that the exoplanet is losing atmospheric mass much faster than expected, allowing planetary scientists the opportunity to study this unique phase of planetary development for gas giants that orbit close to their host star. <a href="https://beccajean.medium.com/what-wasp-69bs-comet-like-tail-tells-us-about-hot-exoplanets-44d66b5494c8">Read More</a>