The X-Ray astronomy group of the Institute of Astronomy Astrophysics & Remote Sensing at the National Observatory of Athens is advertising a postdoctoral position for one year that could be renewed up to a period of three years. The selected candidate will work on the derivation of photometric redshifts for X-Ray sources using machine learning techniques. Experience in the derivation of photometric redshifts and possibly experience in X-Ray Astronomy data analysis are prerequisites. Please send a brief CV including research interests to Dr. I. Georgantopoulos before the 31st of January. The candidate should also send two names of referees who are willing to send a letter in support of their application.