  We report a new way to strongly couple graphene to a superconductor. The
graphene monolayer has been grown directly on top of a superconducting Re(0001)
thin film and characterized by scanning tunneling microscopy and spectroscopy.
We observed a moir\'e pattern due to the mismatch between Re and graphene
lattice parameters that we have simulated with ab initio calculations. The
density of states around the Fermi energy appears to be position dependent on
this moir\'e pattern. Tunneling spectroscopy performed at 50 mK shows that the
superconducting behavior of graphene on Re is well described by the
Bardeen-Cooper-Schrieffer theory and stands for a very good interface between
the graphene and its metallic substrate.
