High-resolution X-ray spectroscopy of lambda Cep

We propose to improve our understanding of structures of stellar winds and theirimplications on the Xray emission of massive stars by collecting ahighquality, highresolution RGS spectrum of the O6Ief supergiant lambda Cep.This object shares many properties with the wellobserved O4Ief supergiant zetaPup which turned out to be an incredible puzzle: its Xray spectrum meets verywell the expectations of the windembedded shock model, although zeta Pup is nota normal. Otype star. This situation contrasts with that of the other morenormal, single Otype stars observed in high resolution so far. lambda Cepoffers a unique opportunity to investigate the Xray emission of the sole twinof zeta Pup, and hence to draw a much clearer picture of the emission of single massive stars. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]