To date, astronomers have discovered thousands of exoplanets, each with a variety of characteristics. An exoplanet named WASP-76b, located 637 light-years away from Earth, is of particular interest. Recently, with its extreme climatic conditions and unique halo phenomenon, it has aroused the curiosity of astronomers.
WASP-76b is a super-hot Jupiter-like planet with a slightly smaller mass than our Jupiter, about 90% of Jupiter's mass, but almost twice its size. Its host star, WASP-76, is a yellow dwarf star that is very similar to our Sun, but the two are very close, 12 times closer than Mercury to the Sun, which means that the distance between the two is less than 5 million kilometers.
This close proximity also exposed WASP-76b to intense stellar photothermal radiation, causing its surface temperature to reach 2400 degrees Celsius, which is high enough to vaporize the metal.
And because of the close proximity of the two, WASP-76b has also been gravitationally locked by its host star, causing it to orbit the host star only on one side, which causes it to have a very high temperature on the star-facing side, which can exceed 2400°C, but the temperature on its side-to-star is very low.
Then this makes a phenomenon on the planet, on its extremely hot side, the temperature is so high that many metals such as iron will also be melted and even vaporized, and these large amounts of gas are heated and expanded and then flow to the colder side, forming an extremely violent wind, some astronomers believe that the wind speed on this planet is as high as 22 kilometers per second, that is, it moves 22,000 meters in one second. On our planet, the wind speed of a Category 17 typhoon is only 62 meters per second. Or that the wind speed on this planet is 355 times that of a Category 17 typhoon on Earth.
In such an extreme environment, WASP-76b has experienced an astonishing climatic phenomenon - iron rain. Astronomers call it "iron rain", a phenomenon that is not found in the solar system and is rare around other stars.
In addition to the iron rain, astronomers recently discovered another amazing phenomenon on the planet WASP-76b, the multicolored halo. The phenomenon was discovered through data provided by ESA's Cheops Exoplanet Signature satellite, as well as other missions. The halo appears in the form of colorful concentric circles that only manifest under certain conditions. This halo effect is different from the rainbow formed by rain on Earth and is caused by the diffraction of matter in the planet's atmosphere under certain conditions. In the figure below, the multicolored halo phenomenon on Venus is on the left, and the multicolored halo phenomenon on the right is the multicolored halo phenomenon on Earth.
WASP-76b is one of the most observed exoplanets by astronomers. Scientists believe that the formation of a multicolored halo requires a set of special conditions to be met. First, there must be spherical particles in the planet's atmosphere that reflect light, and these particles need to be uniform and stable enough for long-term observations.
Second, the stars near the planet need to shine directly on the planet, and the observer needs to be positioned just right. Then the composition of the planet's atmosphere and the color of the light emitted by the stars also affect the color and pattern of the ring. So it's not easy to see this kind of colorful aura.
But on the planet WASP-76b, these conditions were met at one time. The light emitted by its yellowish-white host star, WASP-76, and the material in the planet's atmosphere create an optical phenomenon that creates a colorful halo that reveals the unique climate and atmosphere characteristics of WASP-76b, although the exact reason for its formation remains a mystery.
Source: "Chinese Industry Information" reported on May 7 that "astronomers detected a rainbow-like ring for the first time on exoplanet WASP-76b"