Khaberni - Astronomers have succeeded in drawing the first detailed maps of the outer edge of the sun's atmospheric envelope, a changing boundary where solar materials separate from the sun's magnetic grip and rush into space.
This boundary, scientifically known as the "Alfvén surface," represents the point of no return where solar winds switch from being magnetically-driven to become a free, irreversible stream.
The new maps, which combine direct measurements from NASA's Parker Solar Probe and data from other spacecraft, reveal that this edge is not static but is a living entity that breathes with the rhythm of the sun itself.
As the sun moves toward the peak of its 11-year activity cycle, these boundaries expand and form with rougher, more jagged edges while they shrink and become smoother during periods of solar calm.
Sam Badman, an astrophysics researcher at the Harvard-Smithsonian Center and the lead author of the study published in the Astrophysical Journal, says: "For the first time, we have a precise map that we can use as a guide for navigation in this critical region. More importantly, we now can monitor its changes in real-time and compare it with direct measurements, which gives us a much deeper understanding of the processes occurring around our sun."
This discovery gains particular importance in the field of "space weather," providing scientists a new tool to improve models for predicting solar storms that might disrupt power networks on Earth and endanger astronauts and satellites.
The research also suggests the potential application of these results to understand the behavior of other stars' atmospheric envelopes in our galaxy.
By repeatedly flying through the sun's outer atmosphere, the Parker probe, with the aid of the specialized SWEAP instrument, provided direct samples from the region immediately below the Alfvén surface, accurately confirming the location and timing of the release of solar winds from the sun's magnetic grip.
The scientists indicate that the next phase will involve the probe diving again during the upcoming period of solar calm, allowing them to observe the transformations of these boundaries over a full solar cycle, a step that may bring them closer to solving one of the most complex puzzles in solar physics: why does the sun's corona increase in temperature the further it is from the surface?
