• A spot or patch that appears from time to time on the sun's surface, appearing dark by contrast with its surroundings.

  〔天文〕太阳黑子

  Example sentencesExamples

  • Between the mid-sixteenth and seventeenth centuries, the sunspot cycle shut down, reducing solar output by a mere 0.25 percent.
  • For example, magnetic fields could be added to global simulations of solar convection to address the operation of the dynamo that drives the sunspot cycle.
  • He also used his telescope to discover the four largest satellites of Jupiter, the phases of Venus, and sunspots on the sun.
  • It went on to warn that further flares are likely in the next week, and because the sunspot is moving into line with Earth, the risk of disruptions is even greater as the solar activity will strike the planet head-on.
  • He developed a great interest in broadcast noise, especially during sunspots.

Sunspots are regions of lower surface temperature and are believed to form where loops in the sun's magnetic field intersect the surface; an individual spot may persist for several weeks. The number of sunspots on the solar surface fluctuates according to a regular cycle, with times of maximum sunspot activity recurring about every eleven years