relative sunspot number
šomâr-e bâzâni-ye hurlak
Fr.: nombre relatif de taches solaires
smoothed sunspot number (SSN)
šomâr-e hamvâride-ye hurlakhâ
Fr.: nombre de taches solaires lissé
An average of 13 monthly → sunspot numbers, centered on the month of concern. The 1st and 13th months are given a weight of 0.5.
Fr.: nombre de taches, ~ ~ Wolf
A quantity which gives the number of sunspots at a given time. It is defined by the relationship R = k(10g + f), where R is the sunspot number, k is a constant depending on the observation conditions and the instrument used, g is the number of the groups and f is the number of individual spots that can be counted. Also called the → Wolf number and → relative sunspot number.