Astronomers discover multiple rock-forming elements on Jupiter-sized exoplanet

Using the Gemini North telescope, an international team of astronomers has discovered multiple rock-forming elements in the atmosphere of a Jupiter-sized exoplanet, WASP-76b. The findings, published in the journal Nature, provide insight into how our own Solar System formed.

WASP-76b is a hot Jupiter that lies 634 light-years away in the direction of the constellation of Pisces. The planet orbits its host star at an exceptionally close distance - approximately 12 times closer than Mercury is to the Sun.

Led by Stefan Pelletier, a PhD student with the Trottier Institute for Research on Exoplanets at the Université de Montréal, the research team conducted meticulous observations of WASP-76b during three instances when the planet transited in front of its host star. The researchers found a number of rock-forming elements including sodium, potassium, lithium, nickel, manganese, chromium, magnesium, vanadium, barium, calcium, and, as previously detected, iron.

Due to its close proximity to its host star, these rock-forming elements become vaporized and dispersed throughout its atmosphere. The abundance of many of these elements closely match the abundances found in both our Sun and the exoplanet's host star. This intriguing correlation suggests that gas giants such as Jupiter and Saturn may form more akin to the process of star formation, implying that these massive planets develop from the gas and dust within a protoplanetary disk, rather than through the gradual accumulation and collision of dust, rocks, and planetesimals as seen in the formation of rocky planets such as Mercury, Venus, and Earth.

Another notable finding is the first-ever unambiguous detection of vanadium oxide on an exoplanet.

"This molecule is of high interest to astronomers because it can have a great impact on the atmospheric structure of hot giant planets. This molecule plays a similar role to ozone being extremely efficient at heating Earth's upper atmosphere," says Pelletier.

For the unversed, the Gemini North telescope is one-half of the International Gemini Observatory operated by NSF's NOIRLab.