SIMBAD references

We present differential radial velocity measurements of Proxima Centauri collected over 4 years with the ESO CES with a mean precision of 54m/s. We find no evidence of a periodic signal that could corroborate the existence of a sub-stellar companion. We put upper limits (97% confidence) to the companion mass ranging from 1.1 to 22M_Jup at orbital periods of 0.75 to 3000d, i.e. separations 0.008-2AU from Prox Cen. Our mass limits concur with limits found by precise astrometry (Benedict et al., 1998BAAS...29.1316B and priv. comm.) which strongly constrain the period range 50-600d to 1.1-0.22M_Jup. Combining both results we exclude a brown dwarf or supermassive planet at separations 0.008-0.69AU from Prox Cen. We also find that, at the level of our precision, the RV data are not affected by stellar activity.