This finding, detailed in a research paper on the preprint server arXiv, could significantly enhance our understanding of the atmosphere of Smertrios and its formation.
The atmosphere of Smertrios has been a focal point of study due to its intriguing characteristics. Smertrios orbits the yellow subgiant star HD 149026, located approximately 248.5 light-years from Earth. With a radius of about 0.81 Jupiter radii and a mass roughly three times less than Jupiter, this metal-rich hot Saturn completes an orbit every 2.876 days at a distance of 0.043 AU from its host star. Its equilibrium temperature is estimated to be around 1,693 K.
A team led by Sayyed A. Rafi from the University of Tokyo utilized CARMENES at the Calar-Alto Observatory to perform high-resolution cross-correlation spectroscopy of the atmosphere of Smertrios. Their goal was to gain deeper insights into the atmospheric composition of this exoplanet.
According to the research, the atmosphere of Smertrios was analyzed through transmission spectroscopy, which has proven to be a successful method for studying exoplanet atmospheres. The near-infrared high-resolution transmission spectrum of Smertrios, obtained with CARMENES, revealed evidence of a water vapor signal close to the predicted location. The most prominent signal had a signal-to-noise (S/N) ratio of 4.8, indicating the presence of water vapor in the atmosphere of Smertrios.
While the evidence points towards water vapor, it is not yet a confirmed detection. The study suggests that if the atmosphere of Smertrios is homogeneous and at chemical equilibrium, its carbon-to-oxygen ratio must be less than one, due to the expected low abundance of hydrogen cyanide.
Despite searching for hydrogen cyanide, the researchers found no evidence of this compound in the atmosphere of Smertrios. They attribute this absence to the relatively low S/N ratio of the data, meaning that hydrogen cyanide cannot be definitively ruled out.
Additionally, the study assessed the orbital and rest velocities of Smertrios, measuring approximately 158.17 and 2.57 km/s, respectively. While the orbital velocity aligns with expectations, the rest velocity is notably red-shifted. The researchers propose that this anomaly could be due to unusual atmospheric dynamics or an orbit with non-zero eccentricity.
This study marks a significant step in unraveling the mysteries of the atmosphere of Smertrios, offering new insights into its composition and potential atmospheric processes.
