article_snippet: While it might have looked like a speck of dust at first, this was actually a sunspot on the solar surface, caused by a concentration of magnetic fields.
article_snippet: Sunspots are fairly common, with the number on the surface correlating with how active the sun is.
article_snippet: Sunspots occur when a concentration of magnetic fields causes the surface temperature to reduce, making a specific section stand out from the surroundings.
article_snippet: Sunspots range hugely in size, from just 10 miles (16km) to 100,000 miles (160,000km) - big enough to be seen from Earth without a telescope, and more than ten times the size of our planet.
article_snippet: Sunspots are regions where powerful magnetic fields emanate from the sun .
article_snippet: powerful magnetic fields can get wound up so tightly that powerful magnetic fields rise up from inside the sun, and the sunspots mark the points where this happens.
article_snippet: powerful magnetic fields are much colder than the rest of the sun's surface and usually last a few days before disappearing.
article_snippet: powerful magnetic fields have a temperature of anywhere from 2,700 to 4,200°C (4,890 to 7,590°F), compared to 5,500°C (9,930°F) for the surrounding solar material, which is why powerful magnetic fields are so visible.
article_snippet: Sunspots are also sometimes the source of eruptions on the sun, namely solar flares and coronal mass ejections (CMEs), all of which are linked to magnetic fields.
article_snippet: Sunspots should not be confused with coronal holes, regions of the corona - an aura of plasma around the sun - where the magnetic field reaches out into space rather than looping back down onto the surface.
article_snippet: Sunspots (previous Nasa image shown) are fairly common, with the number on the surface correlating with how active the sun is.
article_snippet: previous Nasa image shown) occur when a concentration of magnetic fields causes the surface temperature to reduce, making a specific section stand out from the surroundings .
article_snippet: In this Nasa image, multiple sunspots can be seen across the solar surface .
highlights_snippet: These were sunspots, caused by concentrations of magnetic fields .
  
highlights_snippet: These are sometimes associated with eruptions such as solar flares .
  