SIMBAD references

The NIST database lists several MnII lines that were observed in the laboratory but not classified. They cannot be used in spectrum synthesis because their atomic line data are unknown. These lines are concentrated in the 2380-2700Å interval. We aimed to assign energy levels and loggf values to these lines. Semi-empirical line data for MnII computed by Kurucz were used to synthesize the ultraviolet spectrum of the slow-rotating, HgMn star HD175640. The spectrum was compared with the high-resolution spectrum observed with the HST-STIS equipment. A UVES spectrum covering the 3050-10000Å region was also examined. We determined a total of 73 new energy levels, 58 from the STIS spectrum of HD175640 and another 15 from the UVES spectrum. The new energy levels give rise to numerous new computed lines. We have identified more than 50% of the unclassified lines listed in the NIST database and have changed the assignment of another 24 lines. An abundance analysis of the star HD175640, based on the comparison of observed and computed ultraviolet spectra in the 1250-3040Å interval, is the by-product of this study on MnII.