2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/6411We present a study of the central parts of the Sagittarius dwarf spheroidal galaxy (Sgr). We found a clear overdensity of Sgr's stars around M~54 (hereafter NS). NS is well represented by a King model and it has the characteristics of a typical dwarf elliptical nucleus. Whether this means that M~54 has spiraled into the potential well of NS or that M~54 is the real nucleus and NS has formed into its potential wells, remains an open question to be addressed.4 pages, 2 figures. To be published in ``Satellites and Tidal Streams'', proceedings of the conference held in La Palma 26-30 May 2003, Spain, eds, F. Prada,D. Martinez-Delgado, T. MahoneyAstrophysicstext