Exoplanet WASP-76b Discovers Halos: A New Rainbow-Like Phenomenon

A CHEOPS space telescope has detected concentric circles of light in rainbow colors on the exoplanet WASP-76b, which is known for its iron rain. This marks the first time evidence of halos, colorful rainbow-like meteorological phenomena, has been found on an exoplanet. The research was published in the journal Astronomy & Astrophysics.

Halos are formed by concentric circles of light in rainbow colors, with red on the outside and purple on the inside. They differ from rainbows as backscattered light is diffracted between water droplets. Halos are also created by water droplets bending light, but they have a different shape and form compared to rainbows. The phenomenon is likened to the halos seen in medieval paintings encircling the heads of saints.

Lead researcher Olivier Demangeon, an astronomer at the Institute of Astrophysics and Space Sciences in Portugal, explains that observing halos outside the solar system requires very specific conditions, such as perfectly shaped atmospheric particles and a clear line of sight to the host star. He adds that this discovery highlights the importance of studying distant worlds and potentially identifying signs of life beyond our solar system.

WASP-76b is unique in that it is so close to its host star that it experiences extreme temperatures, leading to iron rain on the planet’s surface. The discovery of halos on this hot exoplanet may indicate the presence of clouds made of perfectly spherical water droplets that have remained stable over time. Further research is needed to confirm the rarity of halos on exoplanets and understand their formation mechanisms fully. Scientists hope to use similar light phenomena to study distant worlds and potentially identify signs of life beyond our solar system.

This discovery sheds light on new possibilities for exploring and understanding other planets in the universe.