Including all the lines
2 / 2

  (clic sull'immagine per vederla a dimensione reale)  
  A sample section of the spectrum of Sirius at 200 nm observed by Glenn Wahlgren with the Goddard High Resolution Spectrograph on the Space Telescope together with a calculated spectrum that has not yet been adjusted to improve the fit. The rotation velocity is known from fitting lines in the visible observed at high resolution. The spectrum is computed both at 0 km/s rotation velocity to resolve the blends and at 16 km/s. The 16 km/s spectrum was then convolved with the instrumental profile. The resolution was not high enough to resolve the actual structure in the spectrum which is on the order of the zero rotation line width. Around 201.26 for example the two side bumps are washed out. Ideally the measurement should have been made at higher resolution. The calculations are plotted in residual flux but the continuum level for the observed spectrum has not been set and its position can be adjusted. Except at 201.02 nm it appears that the observed spectrum should be moved up about 3\%. That would also bring the minima into better agreement. Either the Mn II line at 201.0259 is wrong or there is a problem with the reduction at this point which is near the end of a scan. Note that the minima in the spectrum at 201.1, 201.22, and 201.42 are not line positions. Features in spectrum are blends of many lines. Note the Si II line at 201.5 that is computed very much too strong. That will be corrected in my next calculation for Si II. Note the missing line at 201.11. That will probably appear when I recompute the Fe group lines using improved laboratory analyses. The linelist for this spectrum has not been updated with new calculations. It uses the linelist from my web site. I am going to update many elements at once to limit the number of versions of the linelist and also to give me more time to make comparisons and to check for errors. Fresh calculations can be found on the website in the {\small /ATOMS} directory.  
R.L. Kurucz