properties of cluster stars, we have restricted our analysis to those X-ray sources with counterparts among photometrically selected cluster members taken from the catalogues of Naylor et al. (2002) and Jeffries et al. (2004).

The EPIC X-ray source list was correlated with: (1) the photometrically selected members based on the D’Antona & Mazzitelli (1997) isochrones and $BVI$ photometry in Naylor et al. (2002 – their Table 6), which incorporates $BV$ photometry of bright cluster members from Clariá (1982); (2) photometrically selected members based on [*either*]{} the D’Antona & Mazzitelli or Baraffe et al. (2002) isochrones and $RIZ$ photometry in Jeffries et al. (2004 – their Tables A.2 and A.3)

The correlation took place in two stages. In stage 1 correlations were sought with bright (maximum log likelihood $>100$) X-ray sources that have small formal position uncertainties. The purpose was to establish how much additional systematic error there might be in the [*XMM-Newton*]{} astrometry and whether there was any systematic offset in the X-ray source positions[^1]. It was found that an offset of 1.48 and 0.05 arcseconds needed subtracting from the RA and Dec of the X-ray positions and that an additional systematic error of 1.2 arcseconds (1-$\sigma$) needed adding in 