While researching rapid changes in the appearance of sunspots, scientists noticed the disappearance, in just one hour, of a huge spot
By: Dr. Noah Brosh
American scientists reported extremely rapid changes that occurred in the appearance of sunspots. While taking measurements, we will see how a large spot, the size of a continent on the Earth - disappears from sight within an hour. Ground observations combined with X-ray measurements from a satellite - a study named after the late Reuven Ramati, an Israeli-born scientist who worked in the USA, showed that in the area of the spot, radiation was released when it disappeared. Analysis of the combined results will provide a better understanding of the nature of sunspots.
Back in ancient times, astronomers noticed black spots on the sun. Evidence of this is also found in Chinese writings from 2000 years ago and in the writings of Greek philosophers from the 4th century AD. In the history of science there is a well-known dispute over the question of who was the first European to notice the spots. It seems to have been in 1611. Paintings from that time show the phenomenon clearly - thanks to the first observations, with telescopes. With the improvement of the instruments, the observations were improved and they were done in an orderly way. The result: a cycle was discovered in the appearance of sunspots. She reaches her climax
once every 11 years.
Today it is clear that the sunspot is colder than the rest of the sun's surface and therefore it appears black. Its heat is low - as a result of strong magnetic fields, which prevent the free passage of heat. While the temperature of the sun's surface is about 5700 degrees - the spot area is about 4000 degrees.
Since the brightness of a body - or part of it - is directly proportional to the fourth power of the temperature, the sunspot area radiates, from each unit of area, only a quarter of the amount of radiation radiated by another area next to it. That's why it looks black to us. The magnetic field is created under the sun's surface and is emitted through the spot, into the sun's atmosphere - the "crown". There is a connection between the spots and solar flares, when huge amounts of plasma are thrown into space. Part of it reaches the Earth and creates the "Northern Lights" and various phenomena in the upper atmosphere.
It is still not clear what is the mechanism that creates solar flares. The American scientists report that an outbreak occurred in the same area from which the stain disappeared. It is possible that this observation will help in understanding the process.
