Two independent research teams have unveiled why the warm gas-giant exoplanet WASP-107 b is unusually puffy. Data from NASA’s James Webb Space Telescope and Hubble Space Telescope indicate that WASP-107 b’s interior is hotter and its core is more massive than previously estimated due to minimal methane (CH4) presence in its atmosphere, according to a NASA report on Monday.
Max Life Savings PlanGet ₹1.02 crores on maturity. Ad The increase in temperature is likely due to tidal heating caused by the planet’s non-circular orbit.
Luis Welbanks from Arizona State University (ASU) explained in a paper published in Nature, “Based on its radius, mass, age, and assumed internal temperature, we thought WASP-107 b had a very small, rocky core surrounded by a huge mass of hydrogen and helium. But it was hard to understand how such a small core could sweep up so much gas and then stop short of growing fully into a Jupiter-mass planet.”
Combining observations from Webb’s NIRCam (Near-Infrared Camera), MIRI (Mid-Infrared Instrument), and Hubble’s WFC3 (Wide Field Camera 3), the team built a broad spectrum of 0.8- to 12.2-micron light absorbed by WASP-107 b’s atmosphere. Using Webb’s NIRSpec (Near-Infrared Spectrograph), they also created an independent spectrum covering 2.7 to 5.2 microns. This high-precision data allowed for the detection and measurement of numerous molecules, including water vapor (H2O), methane (CH4), carbon dioxide (CO2), and ammonia (NH3).
David Sing, the lead author of a parallel study published in Nature, noted, “The fact that we detected so little methane, even though we did detect other carbon-bearing molecules, tells us that the interior of the planet must be significantly hotter than we thought.”
Previously, researchers speculated that tidal heating might explain WASP-107 b’s puffiness, but evidence supporting this was lacking until the Webb results. The teams now believe that the planet’s internal heat significantly churns its atmosphere, offering a new method for estimating the core’s size.
