On April 4, 1947, the largest sunspot group known was being recorded, often referred to as the “Great Sunspot of 1947”. Sunspots are counted in groups rather than individually. That April, this largest group of sunspots eventually covered a total area of the sun’s visible surface that was roughly 330 times the Earth’s surface area. This sunspot group remained observable for several months.
The intense magnetic activity on the sun’s surface creates differences in surface temperatures. These temporarily “cooler” areas, or sunspots, appear darker against the blazing light of their molten surroundings. This relative temperature difference is approximately 1000 K… still quite hot enough to melt all known metals at their “reduced” temperature. Sunspots tend to appear at the sun’s high latitudes. The number increases as the sunspot cycle progresses, and they migrate closer to the solar equator.
Although we now know that the number of sunspots rises and falls in a cycle roughly equivalent to 11 Earth years, the 1947 sunspot remains the record holder.
B Bondar / Real World Content Advantage