James Webb Juan for a less strange exoplanet to answer the long mystery

Some of the most common exoplanets in our galaxy are also the most mysterious. We do not have an equivalent to this type of planet, called sub-neptum, in our solar system, but now the James Webb spatial telescope is revealing details of these planets for the first time.

Small than ice giants like Neptune or Uranus, but with a composition of Saturn or Johpter, sub-neptuns are thought to be the most common type of exoplanet, but they are difficult to study because they are usually obscured by clouds and dimming. This means that astronomers have not been able to study their atmospheres, or learn a lot about how these planets evolve, or why we do not have one in our solar system.

But recently, astronomers were able to use webb to study a sub-neptun named Toi-421 b. “I had been waiting for my whole career for webb, so that we could make sense of the atmospheres of these smaller planets,” said leading researcher Eliza Kempton of the University of Maryland, College Park. “By studying their atmospheres, we are better understanding how sub-neptuns formed and evolved, and part of this is the understanding of why they do not exist in our solar system.”

This particular planet was chosen for study due to its extreme heat, with a fuel of about 1,340 degrees Fahrenheit. This is quite high there should be no methane present in the atmosphere of the planet, which means that it should not form a fog – and therefore it should be easier to observe.

“Why did we observe this planet, toi-421 b? That’s because we thought maybe there would be no Haza,” Kempton said. “And the reason is that there were some previous data that implied that perhaps planets over a certain range of temperature were less involved in moisture or clouds than others.”

Thanks to the lack of moisture, the researchers were able to look at the planet’s atmosphere and see where it was from. They found water vapor, with a large amount of hydrogen in the atmosphere, as well as suggestions of carbon monoxide and sulfur dioxide – but in particular, no indications of methane or carbon dioxide. The large amount of hydrogen was a surprise as it differs from some other subspets that have been observed with the weBB-so can this planet be an abnormality? Or maybe it was formed in another way by these other similar planets?

Researchers hope to observe more sub-neptunes to discover. “We have unlocked a new way to see these sub-neptunes,” said researcher Brian Davenport. “These high temperature planets are suitable for characterization. So, seeing sub-neptunes of this temperature, we are probably more likely to accelerate our ability to learn about these planets.”

The research is published in the letters of astrophysical journals.