Scientists are one step closer to discovering the universe more deeply
In a revelation that has astounded the scientific community, astrophysicists have recently unveiled an astonishing phenomenon: the Sun is emitting gamma rays with energies higher than ever measured before. This groundbreaking discovery not only challenges our existing notions of our nearest star but also underscores the remarkable potential of modern observatories to unravel the mysteries of the universe. Gamma rays, highly energetic electromagnetic waves, are known to be produced by various cosmic sources.
Until now, the Sun was not considered a significant contributor to this high-energy phenomenon. The surprising finding, published in the journal Physical Review Letters, indicates that the Sun is capable of emitting gamma rays with energies reaching up to nearly 10 tera electron volts (TeV). In contrast, the usual energy amount of emitted gamma rays is one electron volt. Scientists collaborating with the Mexican-situated High-Altitude Water Cherenkov Observatory (HAWC) detected the gamma rays.
What sets HAWC apart from other observatories is its continuous operation, allowing scientists to monitor the sky around the clock. Using an innovative setup consisting of 300 large water tanks, each filled with around 200 metric tons of water, HAWC is uniquely positioned to detect the aftermath of gamma rays colliding with Earth's atmosphere. These collisions generate particle explosions called air showers, which, though invisible to the naked eye, create detectable Cherenkov radiation when interacting with water in HAWC's tanks.
“In this particular energy regime, other ground-based telescopes couldn’t look at the sun because they only work at night,” Mehr Un Nisa said. “Ours operates 24/7.”
An international collaboration comprising over 30 institutions across North America, Europe and Asia was at the helm of the discovery. The findings defy prior assumptions about the Sun's emission capabilities and raise intriguing questions about the nature of the solar processes responsible for producing such high-energy gamma rays.
Mehr Un Nisa, a postdoctoral researcher at Michigan State University and the author of the study, remarked, "The Sun is more surprising than we knew… We thought we had this star figured out, but that’s not the case." Nisa and her team began collecting data in 2015, and after years of analysis, they stumbled upon an excess of gamma rays in the solar emission spectrum. These gamma rays possess energy levels exceeding one trillion electron volts (1 TeV), far higher than the energies of visible light emitted by the Sun.
This groundbreaking finding extends the realm of gamma ray exploration, as previous observations were limited by the capabilities of telescopes, such as NASA's Fermi Gamma-ray Space Telescope. The Fermi telescope, launched in 2008, could only detect gamma rays with energies of up to 200 billion electron volts. The HAWC Collaboration's discovery of gamma rays with energies up to nearly 10 TeV provides a crucial advancement in understanding solar phenomena.
The revelation not only highlights the significance of HAWC's innovative technology but also raises new questions about the mechanisms underlying the Sun's unexpected gamma ray emissions. The interaction between solar processes and the Sun's magnetic fields could hold the key to this intriguing phenomenon, sparking further investigation and potentially leading to revolutionary insights about our own star.
As scientists scratch their heads over these newfound observations, one thing remains clear: the Sun continues to be a source of fascination and surprise. "It’s making us see things in a different light. Literally," Nisa concluded, underscoring the transformative power of groundbreaking discoveries that push the boundaries of our understanding of the cosmos. With HAWC leading the charge, the universe's secrets are gradually being unveiled, allowing humanity to gaze deeper into the cosmic unknown than ever before.