- Astronomers in Japan have observed the strongest magnetic field ever directly measured on the surface of the Sun.
- The researchers using the HINODE spacecraft determined that the field was generated as a result of gas outflow from one sunspot pushing against another sunspot.
- “HINODE’s continuous high-resolution data allowed us to analyse the sunspots in detail to investigate the distribution and time evolution of the strong magnetic field and also the surrounding environment.
Magnetism & Sunspots:
- Magnetism plays a critical role in various solar phenomena such as flares, mass ejections, flux ropes, and coronal heating.
- Sunspots are areas of concentrated magnetic fields. A sunspot usually consists of a circular dark core (the umbra) with a vertical magnetic field and radially-elongated fine threads (the penumbra) with a horizontal field.
- The penumbra harbours an outward flow of gas along the horizontal threads.
- The darkness of the umbrae is generally correlated with the magnetic field strength. Hence, the strongest magnetic field in each sunspot is located in the umbra in most cases.
- Previously, magnetic fields this strong on the Sun had only been inferred indirectly.
- More surprisingly, the strongest field was not in the dark part of the umbra, as would be expected, but was actually located at a bright region between two umbrae.