sunspot

n.

太阳黑子；雀斑；

复数：sunspots

1. We observe three sunspot groups on the disc.
   在日面上观测到三个黑子群。
2. This is an intriguing theory that droughts tie in with the sunspot.
   这是一个关于干旱与太阳黑子活动周期有关的令人感到有趣的理论。

Sunspot cycle 24: Smallest cycle in 100 years?
The Sunspot-Activity in the Years 1610[ndash]1960
Dark cores in sunspot penumbral filaments
Group Sunspot Numbers: A New Solar Activity Reconstruction
Sunspot activity and the long-term variation of the Sun's open magnetic flux
Computing sunspot equilibria in linear rational expectations models
Investigation of Mass Flows beneath a Sunspot by Time-Distance Helioseismology
Infrared lines as probes of solar magnetic features. XI. Structure of a sunspot umbra with a light bridge.
Infrared lines as probes of solar magnetic features. V - The magnetic structure of a simple sunspot and its canopy
On a Method of Investigating Periodicities in Disturbed Series, with Special Reference to Wolfer's Sunspot Numbers