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 HD 41004 A. Thus, HD 41004 is a unique hierarchical system with a brown dwarf that accompanies the faint M-component, and a planet that orbits the brighter K-component.

Based on observations collected at the La Silla Observatory, ESO (Chile), with the CORALIE spectrograph at the 1.2-m Euler Swiss telescope.

Table 2 is only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbrg.fr (130.79.128.5) or via http://cdsweb.u-strasbrg.fr/cgi-bin/qcat?J/A+A/426/695