(CNN) — A team of astronomers has spotted what they believe is a rainbow-like phenomenon on a planet outside our solar system for the first time, and it could reveal new insights into distant worlds.
Observations by the European Space Agency's Cheops Space Telescope, or Characterization by the ExOPlanets Satellite, have detected a “fame effect” on the ultrahot exoplanet WASP-76b, 637 light-years from Earth.
An artist's illustration shows a rich rainbow-like phenomenon known as the glory effect detected in the atmosphere of exoplanet WASP-76b. That
A halo, often seen on Earth, consists of colorful, concentrated rings of light, and occurs when light reflects off clouds made of a uniform material.
Beyond Earth, the glow's effect was only seen on Venus until Ceobs and other probes picked up an incredibly weak signal. Based on the signal Khufu detected, astronomers believe the atmospheric phenomenon is directly opposite Earth.
The researchers reported details of the observation in the journal April 5 Astronomy & Astrophysics.
“There's a reason why glory has never been seen before outside our solar system: it requires very strange conditions,” lead author of the study, astronomer Oliver Demanjian of the Portuguese Institute of Astrophysics and Space Sciences, said in a statement. “First, you need atmospheric particles that are nearly perfectly spherical, perfectly uniform, and stable enough to observe for long periods of time. The nearest star to the planet must shine directly on it, and the observer (Khufu in this case) must be properly oriented.
A wild and fiery planet
WASP-76b has fascinated astronomers since its discovery in 2013.
The exoplanet orbits very close to its host star, and the intense heat and radiation received from that Sun-like star (more than 4,000 times the amount of radiation Earth receives from our Sun) caused WASP-76b to swell. About the size of Jupiter, the largest planet in our system.
A simulated scene shows Venus (left) and the glory as it appears on Earth. C. Wilson/B. Lavender/ESA
The planet is in synchronous rotation with its star, meaning that one side, called the day side, always faces the star, while the other side of the planet is in perpetual night.
WASP-76B's daytime temperatures reach 4,352 degrees Fahrenheit (2,400 degrees Celsius). The elements that normally make up rocks on Earth melt and evaporate during the day and condense, forming clouds that emit molten iron rain at night.
Astronomers decided to use a number of observatories, including Kufu, the Hubble Space Telescope, the now-retired Spitzer Space Telescope and NASA's planet-hunting TESS mission, to study what the light imbalance caused as WASP-76b orbited. . in front of its host star.
Combined data from Cheops and TESS, or the Transiting Exoplanet Survey Satellite, indicated that the anomaly could be caused by some mysterious event in the atmosphere.
As the planet passed in front of its star, CHAPS captured data from WASP-76b, making 23 observations over three years.
When astronomers looked at the data, they noticed an unusual increase in light coming from the planet's eastern “terminator,” or the boundary light between the day and night sides. Meanwhile, the Western Terminator emits less light.
“This is the first time that such a sharp change in the brightness of an exoplanet, its 'phase curve,' has been detected,” Demonjian said. “This finding leads us to hypothesize that this unexpected brightness may be caused by a strong, localized and anisotropic (directional) reflection: the glory effect.”
Demanjian said he was excited to be involved in the first detection of this type of light from space.
“It's a special feeling, a certain satisfaction that doesn't happen every day,” he said.
Colorful light on alien worlds
Glory and rainbows are not the same thing. A rainbow is formed when light bends as it passes successively through two media of different densities, from air to water. As light bends, it splits into different colors, creating a rainbow.
But the glory effect is created when light moves through a narrow opening and bends, creating colorful, patterned rings.
If astronomers were to actually see WASP-76b's halo effect, it would mean that the planet had a persistent cloud of perfectly spherical bubbles, or clouds, constantly filling it. In any case, the presence of such clouds indicates that the planet's atmosphere has a constant temperature.
What exactly is in WASP-76b's clouds remains a mystery, but it could be iron, as this element has previously been detected in the planet's clouds.
An artist's illustration shows a night view of exoplanet WASP-76b, where iron rains from the sky. M. Kornmesser/ESO
“What's important to note is that there's an incredible amount of what we're witnessing. Standing is not involved in the study,” Matthew Standing, a researcher at the European Space Agency who studies exoplanets, said in a statement.
“WASP-76b is several hundred light-years away: an ultra-hot gas giant planet showering molten iron,” Standing said. “Despite the confusion, (the researchers) seem to have found possible signs of a pride. “It's an incredibly weak signal.”
If astronomers can observe the faint signal from an event like Magnificence hundreds of light-years away, they may be able to detect the presence of sunlight reflected from extraterrestrial waters in the future, according to researchers.
“More evidence is needed to say definitively that this enigmatic 'extra light' is a rare phenomenon,” said Theresa Luftinger, project scientist for the European Space Agency's Aerial Mission, in a statement. She did not participate in the study.
Ariel, or the Large Atmospheric Remote Sensing Infrared Survey, is expected to launch in 2029.
Luftinger said he hopes the James Webb or Ariel Space Telescope will help test the presence of the glory effect on WASP-76b.
“Other exoplanets can still proudly display the colors that shine,” he said.
