Wolf number
[ woo lf; French vawlf ]
/ wʊlf; French vɔlf /
noun Astronomy.
a number indicating the degree of sunspot activity on the sun as a factor of observer idiosyncrasies, the number of sunspot groups, and the number of individual sunspots.
Also called
relative sunspot number,
sunspot number.
Origin of Wolf number
1975–80; after Rudolf
Wolf (1816–93), Swiss astronomer