A Rainbow in Space? New Observations Reveal a Bizarre Phenomenon on WASP-76b

Saturday - April 13 2024, 01:26 UTC - 7 months ago

New observations from the CHEOPS space telescope have revealed a mysterious "glory" in the atmosphere of WASP-76b, a highly unusual exoplanet. This "rainbow" phenomenon, caused by intense radiation from the planet's star, has been confirmed by detailed observations over a period of three years. If verified, this would be the first detection of a glory outside of our solar system and adds to the list of extreme and fascinating characteristics associated with WASP-76b.

The discovery of WASP-76b, an exoplanet twelve times closer to its star than Mercury is to the Sun, has presented a unique opportunity for astronomers to study strange and extreme phenomena. In particular, the CHEOPS space telescope, operated by the University of Geneva and the European Space Agency, has provided new insights into this mysterious planet. Through extensive observations, a team of researchers has uncovered a peculiar asymmetry between the eastern and western terminators of WASP-76b, indicating the presence of a phenomenon known as a "glory" in the planet's atmosphere.

The unusual properties of WASP-76b have fascinated scientists since its discovery in 2013. With its extreme proximity to its star, the exoplanet is subjected to intense radiation levels, causing it to "inflate" and become almost twice as large as Jupiter, despite being 10% less massive. The day side of WASP-76b experiences scorching temperatures of 2,400 degrees Celsius, which is hot enough to melt elements that are normally solid on Earth. The resulting iron vapor condenses into clouds on the planet's night-side, forming a river of molten iron that rains down on the surface.

However, the real surprise came when researchers turned their attention to the terminator, the imaginary line that separates the day and night sides of a planet. Through detailed observations with the CHEOPS telescope, they discovered that the terminator to the east of WASP-76b was consistently brighter than the one to the west. This observation could not be explained by known physical processes and led the team to propose a novel hypothesis: the existence of a "glory" in the planet's atmosphere, similar to a rainbow on Earth.

To test this theory, the team used CHEOPS to observe twenty-three secondary eclipses (when the planet passes behind its star) and several phase curves (continuous observations during a complete orbit) over a period of three years. Combining these new data with those from other telescopes, the researchers were able to confirm the excess luminous flux on the eastern side of the planet, suggesting the presence of a glory phenomenon. If confirmed, this would be the first detection of this phenomenon outside of our solar system.

The discovery of a glory on WASP-76b has opened up a new realm of possibilities for exoplanet research. Not only is it a remarkable finding in its own right, but it also demonstrates the powerful capabilities of the CHEOPS telescope in revealing the mysteries of our universe.