Thanks to the James Webb telescope, astronomers discovered a hot lava planet made of diamond that developed a second atmosphere after the host star destroyed the original atmosphere.
Planet 55 Cancri e is located about 41 light-years from the solar system and is nearly twice as wide as Earth and nine times more massive. Among the exoplanets that scientists have classified over the years, 55 Cancri e belongs to the super-Earth group, meaning it is more massive than Earth but lighter than Neptune and Uranus.
This exoplanet is so dense that astronomers hypothesize it is made mainly of carbon compressed into diamond. The exoplanet is located 2.3 km from the host star 55 Cancri A, equal to 0.01544 times the distance between Earth and the Sun. Such a distance means that 55 Cancri e only takes about 17 Earth hours to complete one revolution around the host star and has a surface temperature of about 2,400 degrees Celsius.
Radiation from the host star caused 55 Cancri e to lose its original atmosphere, similar to other rocky planets orbiting the host star at too close a distance. However, research published on May 8 in the journal Nature revealed a thick layer of gas surrounding the planet, proving that it has developed a second atmosphere. According to Renyu Hu, a researcher at the California Institute of Technology (Caltech), this atmosphere may be supported by gas escaping from the rock layer inside 55 Cancri e.
55 Cancri e was discovered in 2004 through its influence on the host star’s motion, called the radial velocity exoplanet detection method. In 2016, the Hubble space telescope determined that 55 Cancri e’s atmosphere contained hydrogen and helium.
There are two possible explanations for the atmosphere of 55 Cancri e. First, the super-Earth could be a lava world with a thin, volatile silicate atmosphere. The atmosphere is made up of volatile chemical compounds containing carbon, nitrogen, hydrogen and sulfur, which can be lost by radiation from the host star. The other case is a planet with a thick sub-atmosphere that formed over time through volcanic activity. To find out which was the case, Hu and his colleagues examined the James Webb Space Telescope’s observations of the planet as it passed behind its host star 55 Cancri A. The data ruled out the first possibility, hot lava. flow helped 55 Cancri e develop a second atmosphere.
“55 Cancri e is so close to its host star that it receives a lot of heat in the form of radiation, keeping the temperature on the planet high. At this temperature, everything on the planet melts. The process of gas escape from rocks The melting supports the formation of a second atmosphere,” Hu explained.
According to Hu, 55 Cancri e’s initial atmosphere consisted mainly of hydrogen and helium. However, the research team is not yet sure about the composition of the second atmosphere. While Webb’s observations were inconclusive, models used to interpret the measurements indicated large amounts of carbon dioxide and carbon monoxide.