Produced by: Tarun Mishra Designed by: Manoj Kumar
Astronomers have detected water vapor in the atmosphere of HD 149026 b, an exoplanet also known as "Smertrios." This discovery may help solve the mystery of the planet's unusual formation.
Credit : Wikimedia Commons
Smertrios orbits a yellow subgiant star, HD 149026, located 247 light-years from Earth. The planet completes its orbit in under three Earth days and is classified as a "hot Saturn."
Due to its proximity to its star, Smertrios is tidally locked with a dayside temperature reaching up to 2,600 degrees Fahrenheit (1,420 degrees Celsius), while its nightside remains cooler.
Smertrios is one of the most metal-rich and dense gas giants known. Its metallicity, or ratio of metals to hydrogen, is much higher than that of other hot Saturns and hot Jupiters, as revealed by the James Webb Space Telescope.
The planet has a large solid core contributing to its high density, defying current formation models for hot gas giants.
Researchers used the CARMENES spectrograph at the Calar Alto Observatory in Spain to study Smertrios' atmosphere. This instrument detects the chemical fingerprints in the planet's atmospheric composition.
Contrary to typical hot gas giants, the atmospheric winds on Smertrios appear to blow from the nightside to the dayside, as indicated by red-shifted absorption spectra during transits.
Additional observations are needed to confirm the presence of water vapor and to investigate other atmospheric elements. Researchers aim to determine the planet's metallicity and carbon-to-oxygen ratio to understand its formation history.
The team continues to collect transit observation data to refine their findings. They hope to elucidate the formation and evolution of Smertrios, with preliminary research published on arXiv.