Largest sunspot group
- Who
- The Great Sunspot Group of 1947
- What
- 18000000000 square kilometre(s)
- When
- 08 April 1947
The largest sunspot ever recorded was in the Sun's southern hemisphere on 8 Apr 1947. Its area was about 18 billion km2 7billion miles2, with an extreme longitude of 300,000km 187,000miles and an extreme latitude of 145,000km 90,000miles.
Sunspots appear darker because they are more than 1,500°C 2,700°F cooler than the rest of the Sun's surface temperature of 5,504°C 9,939°F. This giant sunspot group was equivalent to 36 times the surface area of the Earth.
To be visible to the protected naked eye, a sunspot must cover about one two-thousandth part of the Suns disc and thus have an area of about 1300millionkm2 500millionmiles2.
To be visible to the protected naked eye, a sunspot must cover about one two-thousandth part of the Suns disc and thus have an area of about 1300millionkm2 500millionmiles2.