Wolfgang Schmidt, Rolf Schlichenmaier, Nazaret Bello González, Franziska Stief

The Laser Absolute Reference Spectrograph (LARS) is a novel scientific instrument for solar observations with the Vacuum Tower Telescope (VTT) on Tenerife. It works as a combination of the high-resolution Echelle Spectrograph of the VTT with an state-of-the-art, ultra-precise Laser Frequency Comb. The solar spectrum is then calibrated by the Frequency Comb spectrum on an absolute scale. Resulting Doppler shifts of spectral lines reach an accuracy of m/s. In this talk, I will present systematic observations of the convective blue-shift in the solar photosphere. The recent data reveal the absolute velocities and the center-to-limb variation for several spectral lines in the visible spectral range. I will present the bisectorial C-shape profiles and systematical variations for Fe I 630.15nm. On behalf of the SOLARNET project, I want to encourage the audience to perform Service-Mode operations with LARS. Co-observations with other telescopes and instruments would provide e.g. spectro-polarimetric solar observations on an absolute wavelength scale.