A time-series VI study of the variable stars of the globular cluster NGC 6397. Ahumada, J. A. ; Arellano Ferro, A. ; Bustos Fierro, I. H. ; Lazaro, C. ; Yepez, M. A. ; Schroeder, K. P. ; Calderon, J. H. Abstract Publication: New Astronomy Pub Date: 2021 Bibcode: 2021NewA...88j1607A