4 Conclusions

The RGS and LETGS spectra of the corona of Procyon below 40 Å are dominated by the H- and He-like transitions of C, N, and O and by Fe XVII lines. Above 40 Å the LETGS spectrum shows many L-shell lines of e.g., Ne, Mg, and Si, together with lines of Fe VIII-XIII of which the Fe IX line at 171.075 is very prominent. All methods applied in Sect. 3.2 to the spectra of the RGS+MOS and the LETGS show temperatures of the corona of Procyon between 1-3 MK. No indication for a considerably higher temperature component ($T \ga$ 4 MK) is found. The total EM obtained using RGS and LETGS is about $4.1(.5) \times 10^{50}$ cm^-3. The EM distribution shows a smooth continuous structure without separated peak structures. Our results improve on those of Schmitt et al. (1996) who obtain an EM distribution with a maximum temperature around 1.6 MK and a cutoff beyond 6.3 MK. No significant variability of the coronal conditions took place between the observations by RGS and LETGS.

The abundances of C and N, relative to O are somewhat higher ($\sim$factor 1.5) than the values obtained in the solar photosphere (Anders & Grevesse 1989). The Fe abundance is about 1-1.5 $\times$ solar. No significance for a FIP effect, as observed in the solar corona (Feldman et al. 1992), is found. The same was concluded by Drake et al. (1995), based on EUVE observations. This result is an exception of the trends found by Audard et al. (2001c) for RS CVn systems and by Güdel et al. (2001c) for solar analogs. These authors have found indications for the evolution from an inverse FIP effect for highly active stars - via the absence of a FIP effect in intermediately active stars - towards a normal FIP effect for less active stars. Clearly, the weakly active star Procyon does not fit into this picture.

Acknowledgements

The Space Research Organization Netherlands (SRON) is supported financially by NWO. The PSI group acknowledges support from the Swiss National Science Foundation (grant 2100-049343). We are grateful to the calibration teams of the instruments on board XMM-Newton and Chandra. We thank Nancy Brickhouse and Jeremy Drake for their efforts to obtain a long LETGS observation. Finally, we are grateful to the referee for helpful comments.