In this paper the first disk-integrated solar VUV line spectrum is presented, with sufoncient spectral resolution to resolve details of the emission line profile. The full-disk C IV (1548 A) line was constructed using a SUMER/SOHO raster of the whole solar disk. The resulting spectral profile is similar to the one of the solar-like star αCen A, however, with the pointed difference that the net line shift of CIV on αCenA shows a four times larger net redshift than on the Sun. This might indicate a signioncantly higher magnetic activity in the chromospheric network of αCenA as compared to the Sun. A comparison of the solar spectral profile to luminous cool giants shows a remarkable similarity, especially concerning the line asymmetry. While it was suggested in previous studies that the asymmetries in the giants might be due to absorption in the stellar wind, the present study presents evidence, that the cool giant asymmetries could also be due to surface structure on the giant, most probably the large scale convection pattern on those stars. In conclusion, this study shows the urgent need of fulldisk solar VUV spectra with sufficient spectral resolution (>20 000) to conduct solar-stellar studies. When developing future space VUV instrumentation this full-Sun aspect should be considered.
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