EUROPEAN SOUTHERN OBSERVATORY La Silla - Science Operation Department

New telescope baffle

Following the study of Alain Gilliotte (75241-7.ps) a new baffle system has been built and partly installed at the telscope. Three out of four rings have been fixed to the tube, the last ring is mounted on the FEROS adapter and will be a fix part of the system from February on when FEROS is mounted permanently. First test have been made comparing the flatfields before and after installation. The new flats show a slightly higher light concentration and a dark ringlike vignetting effect.

Actions to be taken:

The zero-points will be determined in photometric nights (can be done with data from service programs) and compared to the old zero-points. The source for the vignetting shall be found. The effect of the new baffle on the light concentration shall be checked by moving a bright star in positions in the gap or close to the chip as done in Alains simulations.