Astronomers compiled a cloud atlas to analyze the compositions of the clouds surrounding exoplanet atmospheres.
The cloud atlas, published in Nature Astronomy on May 25, was employed to analyze the clouds that researchers found blocked their view of exoplanets.
Exoplanets, or “hot Jupiters,” are gas giant planets orbiting at faster rates than the planet Jupiter typically would. As a result, exoplanets exist at extremely high temperatures, according to Jonathan Fortney, a professor of astronomy and astrophysics at UC Santa Cruz and a co-author of the paper.
While attempting to observe exoplanets and their atmospheric composition, researchers found that they were unable to do so because of clouds and hazes obscuring their view.
“Our work seeks to understand what these clouds and hazes are made of, how their spatial distribution varies with planet temperature and gravity,” said Peter Gao, a postdoctoral 51 Pegasi b Fellow at UC Berkeley and first author of the paper, in an email.
Gao added that the main goal of the research was to provide scientists with the ability to analyze the cloudiness levels of exoplanets and indicate the easiest time to view them for future studies and observations.
Using computer simulations of cloud and haze particles of Earth water and ice clouds, researchers compared previous data collected from the Hubble Space Telescope and were able to detect the composition, location and obscurity levels of the exoplanet clouds, according to Fortney.
“This is the very important step toward fully characterizing the atmosphere properties of those planets,” said Xi Zhang, an assistant professor of planetary sciences at UC Santa Cruz and a co-author of the paper.
According to Zhang, the unpredictable nature of clouds could not be analyzed based on patterns of temperature alone. Instead, researchers found that cloud visibility in certain temperatures was caused by the materials of the clouds themselves.
Astronomers discovered exoplanet clouds are composed of materials like silicates, aluminum oxide and titanium oxide, and the hazes surrounding the “hot Jupiters” contained hydrocarbons. For instance, Gao explained, these materials would cause clouds to not surround exoplanets at extremely high temperatures of greater than 2,200 K.
Fortney explained that researchers hope to continue testing their discoveries with the arrival of technology like the James Webb Space Telescope. According to Fortney, the James Webb Space Telescope has more advanced capabilities compared to the Hubble Space Telescope.
Additionally, Fortney said researchers aim to employ the computer model they used to observe atmospheres of Earth-like planets in future studies.
Gao added that the results can be expanded to other objects in space with similar temperature levels, such as brown dwarfs, which are also known as “failed stars,” to analyze their evolution processes.
“Our study adds another piece to the puzzle of how planets form in the Universe,” Gao said in the email.