Javaraiah, J
(Astronomical Society of the Pacific, 2003)
Using the data on sunspot groups of life span (T, in days) 2-12day during 1874-1981 we find: (i) the average area (A, in millionth of solar hemisphere) of a spot group increase with T as A(T) = 15.24 exp (T/4.48); and (ii) ...