What To Know
- This active region of the Sun has just been the scene of a series of remarkable solar explosions, culminating in a rare X-class flare.
- The solar flare grading scale is a tool used to measure the intensity of solar flares based on the energy released.
- An M-class flare is ten times more powerful than a C-class flare, and an X-class flare is ten times more powerful than an M-class flare.
A gigantic sunspot, designated AR3664, has just given us one last show as it rotates out of our terrestrial view. This active region of the Sun has just been the scene of a series of remarkable solar explosions, culminating in a rare X-class flare.
What is a solar flare?
A solar flare is an impressive astronomical phenomenon that occurs on the surface of the Sun. It is manifested by a sudden and violent release of energy into the solar atmosphere. This release of energy can manifest itself in different forms, including coronal mass ejections (CMEs), X-ray flares and ultraviolet flares. At the root of these phenomena are sunspots, regions on the solar surface where the magnetic field intensity is particularly high. When these magnetic fields conflict or rearrange, this can lead to an explosive release of energy, projecting charged particles and generating emissions of electromagnetic radiation across the electromagnetic spectrum. The solar flare grading scale is a tool used to measure the intensity of solar flares based on the energy released. It has several categories, identified by the letters A, B, C, M and Xeach representing a energy release ten times higher than the previous category. For example, an M-class flare is ten times more powerful than a C-class flare, and an X-class flare is ten times more powerful than an M-class flare.
A record eruption
On May 10, the sunspot known as AR3664 is believed to have triggered a X5.8-class flare. This was followed in the last few hours by three more X-class flares, including a spectacular peak reaching X8.7. It is the largest solar flare of the current eleven-year cycle.
X8.7-class solar flare erupts from sunspot AR3664 on May 14, 2024. Credit: NASA/SDO We know that X-class flares can have a major impact on radio communications, power grids, and satellites orbiting Earth, so it will be important to be vigilant in the coming days. Radio outages in Australia and East Asia have already been reported, with frequencies of 20 MHz or lower experiencing near-complete disruptions. However, despite the magnitude of this latest flare, it is unlikely to trigger auroras visible further south than usual due to the location of the associated sunspot, according to the NOAA Space Weather Prediction Center.
