Abstract
Stellar rotation has its origin in stellar formation, when the angular momentum of the parent cloud is transferred to the newer stars. The equatorial rotation V can be calculated from the radius and rotation periods by V=2π R/P. The mean <sin i>, since i is the inclination angle between the stellar rotation axe and the line of sight, of a sample of observational data is estimated from the ratio between the mean of the projected velocity <Vsin i> and the mean of the equatorial rotation <V>. In the literature, the mean inclination angle always adopts a value of π/4 independent of the particularities of the stellar population or the data sample under study. Such a procedure not infrequently leads to divergences between theoretical models and observed data. The present work intends to find out the real mean inclination angle for a set of stars in Pleiades cluster. This work fits the distribution function of the true rotation of a sample of Pleiades stars with the generalized distribution function, named q-Maxwellian function. Also we determine the q value by fitting the projected rotational velocity distribution of those stars. Finally the q values obtained from the fitting procedures are used to estimate the mean <sin i> for such Pleiades sample producing a good result when compared to mean values from the observational data.
