Wolf number

短语

词形变化

Wolf numbers 复数 Wolf numbers

释义与例句

n.
  1. 1.

    A measure of the number of sunspots and groups of sunspots present on the surface of the Sun.

词源

The idea of compiling the information about the sunspot number from various observers originated with Rudolf Wolf in 1848 in Zürich, Switzerland.

来源：wiktionary