24 Hours of Rainbow

Honorable mention in the 2023 IAU OAE Astrophotography Contest, category Still images with smartphones-mobile devices: 24 Hours of Rainbow, by Fabrizio Guasconi.

This panoramic view of Livorno, Italy, showcases a series of vivid rainbows captured on three different days in December 2021. Rainbows are the result of sunlight being refracted by water droplets suspended in the air, typically after rainfall or during misty conditions. The water droplets act like a prism, breaking up (refracting) the sunlight into the various colours. The different wavelengths of light are refracted by different amounts, which is why we see this layering of colours. The photographer skillfully merged the most remarkable shots taken on different days to highlight the diverse sizes and brilliance of these rainbows. The locations at which the rainbows appear to be centred are different because each rainbow appeared when the Sun was at a different position in the sky. This composite image beautifully captures the transient yet mesmerising allure of rainbows, illustrating their fleeting appearance and gradual dissipation influenced by the shifting atmospheric conditions. It receives an honourable mention in the category of Still images taken exclusively with smartphones/mobile devices.

Credit: Fabrizio Guasconi/IAU OAE (CC BY 4.0)