Solar Cycle 23 peaked between 2000-2002, and Solar Cycle 24 began in early 2008. It’s normal for the old and new sunspot cycles to overlap for a time before the old one completely fades away, but Solar Cycle 24 has been very slow to ramp up. This pair of images from the Solar and Heliospheric Observatory (SOHO) spacecraft shows sunspots (bottom) and ultraviolet light (top) emitted by the Sun on April 29, 2009. The Sun continued its quiet behavior, with only two small sunspots visible at far right. If you map the location of the spots on the Sun’s surface over the course of a solar cycle, the pattern they make is shaped like a butterfly. The reason for the butterfly pattern is that the first sunspots of each new solar cycle occur mostly at the Sun’s mid-latitudes, but as the solar cycle progresses, the area of maximum sunspot production shifts toward the (solar) equator. The location of the April 29 sunspots near the solar equator is one sign that they belong to the previous cycle, however, and not the new one. The Solar Activity collection in our new World of Change series shows sunspot activity since 1999. (Image credit: Sunspot images from MDI Data Services and Information. Ultraviolet images from SOHO Project Website.)
Satnews Daily
April 30th, 2009
SOHO Shows Slower Sunspots
Solar Cycle 23 peaked between 2000-2002, and Solar Cycle 24 began in early 2008. It’s normal for the old and new sunspot cycles to overlap for a time before the old one completely fades away, but Solar Cycle 24 has been very slow to ramp up. This pair of images from the Solar and Heliospheric Observatory (SOHO) spacecraft shows sunspots (bottom) and ultraviolet light (top) emitted by the Sun on April 29, 2009. The Sun continued its quiet behavior, with only two small sunspots visible at far right. If you map the location of the spots on the Sun’s surface over the course of a solar cycle, the pattern they make is shaped like a butterfly. The reason for the butterfly pattern is that the first sunspots of each new solar cycle occur mostly at the Sun’s mid-latitudes, but as the solar cycle progresses, the area of maximum sunspot production shifts toward the (solar) equator. The location of the April 29 sunspots near the solar equator is one sign that they belong to the previous cycle, however, and not the new one. The Solar Activity collection in our new World of Change series shows sunspot activity since 1999. (Image credit: Sunspot images from MDI Data Services and Information. Ultraviolet images from SOHO Project Website.)