Webb Telescope Makes Stunning Observation Of Infernal Planet’s Atmosphere

The future of other worlds shine thanks to the James Webb Space Telescope. In newly published findings from the Webb Early Release Science program, researchers obtained the first-ever detailed chemical profile of an exoplanet’s atmosphere and even figured out the likely shapes of alien clouds in the planet’s sky.

The exoplanet in question is WASP-39b, a gas giant roughly the size of Saturn orbiting near its star about 700 light-years from Earth. Scientists have studied WASP-39b in the past using Hubble and Spitzer space telescopes to identify water in the exoplanet’s atmosphere in 2018, while Webb detected carbon dioxide on the planet for the first time. in August.

But Webb’s new observations released on Tuesday offer a much broader and more detailed view of WASP-39b’s atmosphere, and even provide clues as to how such a large planet ended up orbiting closer to its star than the planet Mercury does our Sun. Additionally, the new findings fulfill the overarching goal of the Webb Early Release Science program, which was to test and demonstrate what the new flagship space telescope is truly capable of.

“Without this program, we probably wouldn’t have been able to do this kind of detailed single-planet analysis as quickly and efficiently as we did,” University of Chicago graduate student Adina Feinstein and lead author of a forthcoming article on the new Webb results, tells Reverse. “And the accuracy we’re getting is kind of beyond our wildest dreams.”

What’s new – While previous studies have identified water and carbon dioxide in WASP-39b’s atmosphere, the new research has revealed a wider range of chemicals. Water vapor and carbon dioxide were found, but also carbon monoxide, sodium, potassium and, above all, sulfur dioxide, which had never been detected in an exoplanet atmosphere before. .

“What’s really interesting about sulfur dioxide is that the only way to get that in a planetary atmosphere is through a process called photochemistry,” Feinstein says. “So this is one of the first evidences that we have of star-planet interaction, where because the planet is so close to its star and it becomes highly irradiated, you can get these kind of species that were formed.”

NIRSPEC doesn’t take images, but it can break down light coming from an object to detect hidden chemistry.

The findings also help explain how WASP-39b came into orbit so close to its star, she adds. New data from Webb shows a low carbon-to-oxygen ratio in the exoplanet’s atmosphere, which means there are many more oxygen-containing molecules present, such as water vapor, than there are. containing carbon, such as methane, which did not appear in the new findings at all.

Because carbon-containing molecules tend to accumulate more on planets when they are further away from a star, according to Feinstein, with less carbon accumulating if that planet migrates closer to a star, scientists now believe that WASP-39b formed very far from its star, not anywhere near where it is today during its very short orbital period, and then migrated inwards “, she says.

As powerful as the Webb Telescope is, it cannot directly image a planet as distant as WASP-39b, and instead picks up information carried by light from its star as it passes through the exoplanet’s atmosphere as the planet passes in front of its star from Webb. advantageous position. But this information provides more than the chemical fingerprints of WASP-39b’s atmosphere; it may also help scientists paint a picture of what the exoplanet would look like if humans could visit it. Evidence from the new Webb data suggests, for example, “WASP-39b has what is called patchy clouds around the planet’s terminator, which is very similar to what we see here on Earth, where we have regions with a lot of clouds and regions with few clouds,” says Feinstein.This is one of the first tentative evidences of this type of cloud structure on an exoplanet.

The results are detailed in five papers still awaiting publication, but publicly available on the academic preprint server arxiv.org.

How did they do it? — The basics of the new WASP-39b observations have been proven: scientists point a telescope at a distant star and wait for an exoplanet to pass between the star and the telescope, “transiting” the star. The telltale dip in a star’s brightness caused by the passage of an exoplanet is one of the methods used by exoplanet hunters to find these alien worlds in the first place, but scientists can also study these exoplanets by observing starlight passing through the planet’s atmosphere during a transit. .

Webb can supercharge these observations of the exoplanet’s atmosphere thanks to the scale and power of the new telescope. With a main mirror that is 21 feet in diameter, compared to Hubble’s eight-foot mirror and Spitzer’s 2.8-foot mirror, Webb can simply gather and magnify a lot more light, seeing and revealing more.

But record-breaking optics are only part of the story. Webb’s finely tuned instruments, put through their paces in the Early Release Science program, were able to analyze information out of reach and irrelevant to Hubble and Spitzer.

It was the near-infrared imager and slitless spectrograph, or NIRISS instrument, for example, that detected the carbon-to-oxygen ratio that tells astronomers a lot about the origins of WASP-39b.

“Hubble didn’t have the resolution we needed to be able to solve this feature,” Feinstein says.

Meanwhile, it was Webb’s near-infrared spectrometer, or NIRSpec, that detected sulfur dioxide that demonstrates active photochemistry occurring on WASP-39b.

Spectrometers like NIRSpec and NIRISS break light down by wavelengths, and since scientists know which molecules absorb light at different wavelengths, the resulting spectrum tells scientists which molecules are or are not present in an atmospheric atmosphere. exoplanet. It turns out that specializing in observing infrared light, which Webb does, is better for this type of exoplanet spectrometry than a more general telescope like Hubble, which observes in the ultraviolet, visible and some infrared.

So far, Webb’s early observations are overperforming to the point of surprising scientists like Feinstein.

“We had to go back and forth between whether we believe the data,” she says, “or whether we believe our old models.”

And after – Under the Early Release Science program, the new findings are intended to help scientists predict what they can expect from Webb in the years to come.

In the short term, according to Feinstein, that means more papers on WASP-39b and other exoplanets from data from the Early Release Science program. And then there are also exoplanet observations going on right now as part of Webb’s first year of official science observations, the first cycle, which includes such fascinating worlds as the TRAPPIST-1 planets, small rocky worlds about 40 light years from Earth.

In the long run, these observations will only become more detailed, helping scientists understand the true range of diversity of worlds outside our solar system, and in turn helping us understand our own place in the cosmos.

“We’re really starting to get a feel for the demographics of what exoplanet atmospheres look like,” Feinstein says. “It really is like the dawn of a new era for exoplanet atmospheres.”

Leave a Reply

Your email address will not be published. Required fields are marked *