astrophysicists are on earth no strangers to WASP-39b, an exoplanet orbiting a star about 700 light-years from Earth, although they’ve never seen it directly. Now the Webb Space Telescope has provided new insights into this distant world: its observations have revealed the recipe list for the planet’s toxic atmosphere.
WASP-39b is a gas giant with the mass of Saturn and the size of Jupiter, but it orbits its star at about the same distance from the Sun as Mercury, making the exoplanet very, very hot. The exoplanet was Discovered in 2011; Webb telescope observations earlier this year uncovered Carbon dioxide lurks in its atmosphere.
Other molecules and chemical compounds have since been identified, including water, sulfur dioxide, carbon monoxide, sodium and potassium. Results are reviewed for publication and currently available on the preprint server arXiv.
“This is the first time we’ve seen concrete evidence of photochemistry — chemical reactions triggered by energetic starlight — on exoplanets,” said Shang-Min Tsai, a researcher at the University of Oxford, lead author of the paper supporting the presence of sulfur dioxide in the planet explains the planet’s atmosphere, in a Publication of the European Space Agency. “I see this as a really promising perspective to advance our understanding of exoplanet atmospheres [this mission].”
Tracking down the chemicals hovering in the atmosphere of a distant world is no easy task. The nearest confirmed exoplanet is 24.9 trillion miles away. Nevertheless, Webb managed to discover such infinitesimal molecules in WASP-39b.
Webb watched the planet, waiting for it to pass in front of its host star; The light from the star illuminated the planet from behind. Webb recorded infrared wavelengths of this light, and scientists can use the wavelengths of light they absorb to infer what chemicals are present in the atmosphere.
Webb’s abilities have broader implications for understanding the diversity of exoplanets in our galaxy in terms of their potential habitability. With its extreme heat and gaseous composition, WASP-39b is certainly not suited to living beings as we know it — but it does show the kind of molecular-level analysis Webb can apply to distant worlds.
“I look forward to seeing what we find in the atmospheres of small, terrestrial planets,” said Mercedes López-Morales, astronomer at the Center for Astrophysics | Harvard & Smithsonian and co-author of recent work in ESA publication.
The data suggested to the researchers that the chemicals in the planet’s atmosphere may be dissolved in clouds and not evenly distributed in its atmosphere. And based on the relative abundance of the chemicals in the atmosphere, researchers believe WASP-39b arose from a clumping of planetesimals over time.
While we don’t know where Webb will point his infrared keep looking, we know that sometime more Exoplanets will be on the agenda. Webb has previously studied the atmospheres of rocky planets in the TRAPPIST-1 system and may return to the system in due course. You can keep up with Webb’s latest goals here.