A pinwheel-shaped sunspot sighted by astronomers at Kitt Peak National Observatory has been labeled by veteran solar observers as ‘unprecedented,’ according to the National Science Foundation. The sunspot, with a diameter about 6 times that of the earth, was spotted on February 19 with the vacuum solar telescope at Kitt Peak.
The average sunspot, which usually appears in photographs as an irregularly shaped dark hole, has a diameter of about 9600 km. The spiral sunspot's diameter approximated 80,450 km. It maintained its shape for about 2 days before it broke up and changed form.