In the era of advanced observational technology, where our ability to explore the universe has reached unprecedented levels, scientists have recently made a surprising discovery, revealing previously unknown aspects of the Sun's energy spectrum. They have observed the brightest and most powerful light ever witnessed from our daytime star.

The ever-fascinating, continuously shining Sun in the sky remains a subject of continuous interest for scientists worldwide. As the nearest star to Earth, the Sun is a crucial element of our planetary system and has a fundamental impact on life on our planet. Knowledge about the Sun, its processes, and energy emissions is essential for understanding a broad spectrum of phenomena, from basic astrophysical processes to climate changes on Earth. However, despite many years of research, the Sun still harbors secrets that scientists are working to unravel.

At the forefront of this groundbreaking discovery is Mehr Un Nisa, a postdoctoral intern at Michigan State University, soon to join the MSU scientific faculty. Nisa is the lead author of an article published in the prestigious journal Physical Review Letters, which extensively discusses the latest findings. The research focused on gamma rays - a form of light with the highest energy. Although gamma rays do not reach the Earth's surface, they leave distinct signatures that scientists were able to identify thanks to the High-Altitude Water Cherenkov Observatory (HAWC).

HAWC, unlike many other observatories, operates around the clock, enabling the observation of phenomena that were previously inaccessible during the day. The observatory's location, situated between two dormant volcanic peaks in Mexico at an altitude of over 5000 meters, provided an ideal place to monitor high-energy astrophysical events.

The primary research tool of HAWC is its 300 large water tanks, with each tank containing approximately 200 tons of water. When gamma rays collide with air in the atmosphere, air showers - explosions of particles invisible to the naked eye - are generated. HAWC detects these showers by observing Cherenkov radiation produced when the shower particles interact with the water in the tanks.

Data collection for this study began in 2015, and after six years of observations, the research team noticed an unexpected excess of gamma rays emitted by the Sun. The team's initial reaction was one of amazement, as Nisa noted: "When we first saw this, we thought, 'There's definitely something wrong. The Sun can't be this bright at such high energy.'"

This discovery challenges previous assumptions about the Sun's behavior and the energy it emits. While it's known that the Sun emits light at various energy levels, the focus has always been on the abundance of certain energy levels. Visible light, which we see from the Sun, has an energy of about 1 electronvolt. However, the latest results show that gamma rays, with much higher energy, are much more prevalent than previously thought.

These groundbreaking studies open new possibilities for exploring the Sun and deepen our understanding of its complex processes. They also underscore the importance of innovative observatories like HAWC, providing scientists with unprecedented opportunities to delve into the mysteries of our universe.