The circumstellar medium surrounding rotating massive stars as grb precursors B. Pérez-Rendón, J. Higuera, G. García-Segura, A. Santillán and L. Hernández-Cervantes EAS Publications Series, 61 (2013) 371-373 Published online: 22 July 2013 DOI: 10.1051/eas/1361059