We present a first analysis of a deep X-ray spectrum of the isolated neutron star RBS1223 obtained with XMM-Newton .
Spectral data from four new monitoring observations in 2005/2006 were combined with archival observations obtained in 2003 and 2004 to form a spin-phase averaged spectrum containing 290000 EPIC-pn photons .
This spectrum shows higher complexity than its predecessors , and can be parameterised with two Gaussian absorption lines superimposed on a blackbody .
The line centers , E _ { 2 } \simeq 2 E _ { 1 } , could be regarded as supporting the cyclotron interpretation of the absorption features in a field B \sim 4 \times 10 ^ { 13 } G. The flux ratio of those lines does not support this interpretation .
Hence , either feature might be of truly atomic origin . \PACS 97.60.Jd 97.10.Ld