Abstracts > Oyirwoth Patrick Abedigamba

We measure the large frequency separation, \Delta\nu and the frequency of maximum amplitude, νmax for 10 Red Clump (RC) single member (SM) stars in Kepler open cluster NGC 6819. We derive luminosities, masses and distance moduli for each individual RC star, from which we get the mean distance modulus of \mu 0 = 11.520±0.03 mag for the cluster. A comparison of the observations with an isochrone of Age = 2.5 Gyr, Z = 0.017 with no mass loss obtained with Padova code using a statistical techniques is made. A fractional mass loss of 5 ± 3 percent is obtained if we assume that no correction to \Delta\nu between RC and red-giant branch (RGB) is necessary. However, models suggest that an effective correction of about 1.9 percent in \Delta\nu is required to obtain the correct mass of RC stars owing to the different internal structures of stars in the two evolutionary stages. In this case we find that the mass loss in the red giant branch is not significantly different from zero. This finding confirms that of Miglio et al (2012). It is clear that the mass estimate obtained by asteroseismology is not sufficient to deduce the mass loss on the red giant branch. However, it is clearly only a few percent at most.