Multi-order TODCOR: Application to observations taken with the CORALIE echelle spectrograph - II. A planet in the system HD 41004

In previous works we reported the detection of a brown-dwarf companion orbiting the faint stellar component of the visual binary HD 41004. This had been achieved by applying the multi-order TwO-Dimensional CORrelation (TODCOR) algorithm to CORALIE spectra. A long-term trend of the primary component had also been detected. In this paper we report follow-up observations that seem to unravel the nature of this long-term trend. The new measurements are consistent with the presence of a 2.5 M-J planet in an eccentric orbit around HD41004 A. Thus, HD41004 is a unique hierarchical system with a brown dwarf that accompanies the faint M-component, and a planet that orbits the brighter K-component.