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We have observed the X-ray transient XTE J0421+56 in quiescence withXMM-Newton. The observed spectrum is highly unusual being dominated by anemission feature at ~6.5 keV. The spectrum can be fit using a partially coveredpower-law and Gaussian line model, in which the emission is almost completelycovered (covering fraction of 0.98_{-0.06}^{+0.02}) by neutral material and isstrongly absorbed with an N_H of (5_{-2}^{+3}) x 10^{23} atom cm^{-2}. Thisabsorption is local and not interstellar. The Gaussian has a centroid energy of6.4 +/- 0.1 keV, a width < 0.28 keV and an equivalent width of 940^{+650}_{-460} eV. It can be interpreted as fluorescent emission line fromiron. Using this model and assuming XTE J0421+56 is at a distance of 5 kpc, its0.5-10 keV luminosity is 3.5 x 10^{33} erg s^{-1}. The Optical Monitor onboardXMM-Newton indicates a V magnitude of 11.86 +/- 0.03. The spectra of X-raytransients in quiescence are normally modeled using advection dominatedaccretion flows, power-laws, or by the thermal emission from a neutron starsurface. The strongly locally absorbed X-ray emission from XTE J0421+56 istherefore highly unusual and could result from the compact object beingembedded within a dense circumstellar wind emitted from the supergiant B[e]companion star. The uncovered and unabsorbed component observed below 5 keVcould be due either to X-ray emission from the supergiant B[e] star itself, orto the scattering of high-energy X-ray photons in a wind or ionized corona,such as observed in some low-mass X-ray binary systems.Comment: 8 pages, 4 postscript figures, accepted for publication in Astronomy  and Astrophysic

Strongly absorbed quiescent X-ray emission from the X-ray transient XTE J0421+56 (CI Cam) observed with XMM-Newton