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B supergiants (BSGs) are evolved stars with effective temperatures between 10to 30 kK and are important to understand massive star evolution. Located on theedge of the line-driven wind regime, the study of their atmospheres is helpfulto understand phenomena such as the bi-stability jump. Key UV features of theirspectra have so far not been reproduced by models for types later than B1.Here, we aim to remedy this situation via spectral analysis that accounts forwind clumping and X-rays. In addition, we investigate the evolutionary statusof our sample stars based on the obtained stellar parameters. We determinedparameters via quantitative spectroscopy using CMFGEN and PoWR codes. Themodels were compared to UV and optical data of four BSGs: HD206165, HD198478,HD53138, and HD164353. We also study the evolutionary status of our sampleusing GENEC and MESA tracks. When including clumping and X-rays, we find goodagreements between synthetic and observed spectra for our sample stars. For thefirst time, we reproduced key lines in the UV. For that, we require amoderately clumped wind (f_infty > ~0.5). We also infer relative X-rayluminosities of ~10^-7.5 to 10^-8 -- lower than the typical ratio of 10^-7.Moreover, we find a possible mismatch between evolutionary and spectroscopicmasses, which could be related to the mass-discrepancy problem present in otherOB stars. Our results provide evidence that X-rays and clumping are needed todescribe the winds of cool BSGs. However, their winds seem less structured thanin earlier type stars. This aligns with observational X-rays and clumpingconstraints as well as recent hydrodynamical simulations. The BSGs'evolutionary status appears diverse: some objects are potentially post-redsupergiants or merger products. The wind parameters provide evidence for amoderate mass-loss rate increase around the bi-stability jump. Abstractabridged

Clumping and X-Rays in cooler B supergiant stars