Interpretation of Unresolved Mossbauer Spectra in Compounds of I~~~*

Recebido em 2 de Setembro de 1971 The Mossbauer-effect absorption spectra of the rare earth tri-iodides, Lal,, Gdl, and Erl, show evidence of unresolved quadrupole splitting. We propose that the electric field gradient (EFG) responsible for the interaction can be associated with a partially filled p hole (hd in the 5s25p6 eiectronic configuration of I-. The quadrupole coupling parameters and isomer shifts are determined from a least squares fitting of the data using as initial estimates the C[" NQR data for equivalent rare earth tri-chlorides. For Lal, , Gdl, and Erl, these ar

BS196: an old star cluster far from the SMC main body

We present B and V photometry of the outlying SMC star cluster BS196 with the 4.1-m SOAR telescope. The photometry is deep (to V~25) showing ~3 mag below the cluster turnoff point (TO) at Mv=2.5 (1.03 Msun). The cluster is located at the SMC distance. The CMD and isochrone fittings provide a cluster age of 5.0+-0.5 Gyr, indicating that this is one of the 12 oldest clusters so far detected in the SMC. The estimated metallicity is [Fe/H]=-1.68+-0.10. The structural analysis gives by means of King profile fittings a core radius Rc=8.7+-1.1 arcsec (2.66+-0.14 pc) and a tidal radius Rt=69.4+-1.7 arcsec (21.2+-1.2 pc). BS196 is rather loose with a concentration parameter c=0.90. With Mv=-1.89+-0.39, BS196 belongs to the class of intrinsically fainter SMC clusters, as compared to the well-known populous ones, which starts to be explored.Comment: 8 pages, 10 figures; accepted by MNRA