λ Ori

In Mayne et al (2007) we use the photometry of Dolan & Mathieu (2001), this is taken in the Johnson-Kron-Cousins system calibrated to Landolt standards. Dolan & Mathieu (2001) use a CMD selection in R, R-I to identify a sample of possible PMS stars for follow-up spectroscopy using Li EW as a membership indicator. For Mayne et al (2007) we use only the photometry of those stars showing significant signs of Li. An empirical isochrone generated for this cluster and added to a relative age ladder yields an age of 3Myrs.