Spectra of the HgMn stars κ Cnc and HR 7775 have been analyzed, under the assumption of local thermodynamic equilibrium (LTE), with respect to the abundance and isotopic mixture of gallium. The primary purpose of the investigation was to level the contradictory results obtained using spectral lines in different spectral regions (Smith 1996). The analysis has been performed by Ga ii lines in the...

Abstract. Spectral features absorbed against some radio quasars exhibit ∼ 50mJy variations, with the lines varying both relative to the continuum and, when several lines are present, even relative to one another. We point out that such variability can be expected as a consequence of refractive scintillation caused by the interstellar medium of our Galaxy. Scintillation can cause independent var...