SIMBAD references

The analysis of twelve high resolution SWP spectra of the HgMn star HD 144206 (υ Her) obtained through the large aperture recorded by the International Ultraviolet Explorer (IUE) reveals that the far ultraviolet flux of this star remained constant over the various observations with IUE, except for one spectrum. The increase of FUV flux in SWP 13513 and the simultaneous brightening of υ Her in the V band could reflect a flare similar to those reported in other late B-type stars. The analysis of two high resolution ELODIE spectra obtained four years apart does not show any variations of the lines, either in reduced intensity nor in radial velocity. The absence of far ultraviolet variability and the reproducibility of the brightness in the V band during most IUE observations do not support the presence of large chemical gradients over the surface of υ Her.