AN EMPIRICAL RELATION BETWEEN CAlI EMISSION FLUX EXCESS AND STELLAR AGE FOR LATE TYPE MAIN SEQUENCE STARS

Making use of a relation proposed by Wielen (1977), a new empirical relation between Call emission flux and stellar age is derived by analyzing Wilson and Woolley's spectroscopic data (1970) of late type main sequence stars (K0-M5) and kinematic properties of those stars given by Gliese (1969). The proposed relation shows that the emission flux excess of the Call H-K lines, $F_k'+F_k'$ introduced by Linsky et al. (1979) decreases with stellar age $\tau$ as $\tau^{-0.51}$, consistent with the inverse square law as noted by Skumanich (1972).