The atmosphere of this planet was first identified by Hubble. In analyzing it, the team identified some compounds that suggest that the planet was formed farther from the star than where it is today, just 7 million kilometers away. Computational models and interpretation of results were led by scientists at the University of Warwick in the United Kingdom, and this was the first time that molecules in the atmosphere were measured to determine their chemical composition.
The study was carried out with the Nazionale Galileo telescope, in Spain, which produced high resolution data from the HD 209458b spectrum during transit on four different occasions. In this, the star’s light is altered as it passes through the planet’s atmosphere, and it was with these differences that astronomers were able to determine the compounds present and their abundance: for the first time, they identified that there was hydrogen cyanide, methane, ammonia, acetylene, carbon monoxide and small amounts of water vapor in the atmosphere.
The large presence and variety of carbon-based molecules indicates that the amount of carbon and hydrogen atoms in the atmosphere is similar, which is twice the number expected by researchers. In practice, this shows that the planet accumulated carbon dioxide while it was forming, something that would be possible only if it was in an orbit farther from the star when it formed – which, possibly, would be similar to the distance of Jupiter and Saturn from the Sun.
Dr Siddharth Gandhi, from the Department of Physics at the University of Warwick, explains that it is not possible for a planet to form with an atmosphere so rich in carbon if it is in the region of condensation of water vapor, so the discovery corresponds to the understanding that planets like HD 209458b, considered a hot Jupiter, formed far from where they are today. Exoplanets get this name when they are gaseous, just like Jupiter, but they orbit around their stars much closer to them than the gas giants in the Solar System.
With future telescopes to come, with more powerful observation capabilities, the same technique could be used to study the chemical composition of exoplanets that, perhaps, could harbor life. Anyway, with these observations, it will be possible to define the types of planet that may exist based on the location in which they were formed and how they evolved: “detecting as many molecules as possible is useful when we advance in testing this technique on planets with friendly conditions for life, because we will need a complete portfolio of chemical species that we can detect ”, concludes Dr. Matteo Brogi, also from the university.
The article with the results of the study will be published in the journal Nature.
Did you like this article?
Subscribe your email to Canaltech to receive daily updates with the latest news from the world of technology.
Get the latest news delivered to your inbox
Follow us on social media networks