Evidence of water found in atmosphere of 'metallic god of war'

Astronomers have found evidence of water vapor in the atmosphere of a super-hot exoplanet called "Smertirios," or "the metal god of war."

This result, reported in a research paper published on arXiv, could be key to better understanding the structure and formation scenario of this strange world.

The planet is officially called HD 149026 b, and is named Smertrios, after the Gaulish god of war and Noricum. It is a "hot Saturnian," a type of exoplanet called a "hot gas giant." These are exoplanets that are similar in size to Jupiter or Saturn but orbit their host stars at very close distances.

The metal-rich planet orbits HD 149026, a yellow supergiant star of spectral type G0 IV, at a distance of about 248.5 light-years.

The planet's radius is about 0.81 times that of Jupiter, and it is about three times less massive than Jupiter.

Previous observations found that Submersible orbits its host every 2.876 days, at a distance of about 0.043 astronomical units. The planet's equilibrium temperature is estimated at 1693 Kelvin.

A team of astronomers led by Syed Ali Rafi of the University of Tokyo in Japan used the CARMENES telescope at the Calar Alto Observatory to perform a high-resolution spectroscopic analysis of the cross-correlation of Smertirius. Their main goal was to gain more information about the composition of the exoplanet's atmosphere.

"Transmission spectroscopy offers one of the most successful methods for studying exoplanet atmospheres," the scientists wrote in their paper. "We have analyzed the high-resolution near-infrared transmission spectrum of hot Saturn, HD 149026 b, taken with the Carmines spectrometer."

By analyzing the Carmenis data, Ravi's team found evidence of a water signal very close to where Semitrius should be.

With a signal-to-noise ratio (S/N), which measures how much information is distorted by noise, of 4.8, this was a finding they couldn't ignore.

Astronomers indicated that this signal is only evidence, and not a confirmed discovery, of the presence of water vapor.

According to the study, evidence of water vapor in the atmosphere of Submersible suggests that the ratio of carbon to oxygen on the planet must be less than one, because the abundance of hydrogen cyanide would be expected to be very low if the atmosphere were homogeneous and in chemical equilibrium.

Although scientists have searched for hydrogen cyanide in the atmosphere of Smetrius, they have found no evidence of this compound. Astronomers speculate that this may be due to the low signal-to-noise (S/N) data set. Therefore, the possibility of hydrogen cyanide in the atmosphere of this planet cannot be ruled out definitively.