We present results of X-ray spectroscopy for TWA~5 , a member of the young TW Hydrae association , observed with XMM-Newton . TWA~5 is a multiple system which shows H \alpha emission , a signature typical of classical T Tauri stars , but no infrared excess .
From the analysis of the RGS and EPIC spectra , we have derived the emission measure distribution vs. temperature of the X-ray emitting plasma , its abundances , and the electron density .
The characteristic temperature and density of the plasma suggest a corona similar to that of weak-line T Tauri stars and active late-type main sequence stars . TWA~5 also shows a low iron abundance ( \sim 0.1 times the solar photospheric one ) and a pattern of increasing abundances for elements with increasing first ionization potential reminiscent of the inverse FIP effect observed in highly active stars .
The especially high ratio { Ne / Fe } \sim 10 is similar to that of the classical T Tauri star TW~Hya , where the accreting material has been held responsible for the X-ray emission .
We discuss the possible role of an accretion process in this scenario .
Since all T Tauri stars in the TW Hydrae association studied so far have very high { Ne / Fe } ratios , we also propose that environmental conditions may cause this effect .