Radial velocity stability

As reported before, when the seeing is variable the RMS value of the radial-velocities measured with the medium-resolution fiber is much worse ($\sim$25 m/s) but when the shaker is used the RMS become $\sim$10 m/s, i.e., nearly as good as under stable seeing conditions. Test with the high-resolution fiber shows it not to be significantly affected by variations in seeing and we found the intra-night velocity accuracy with this fiber to be 4-6 m/s. Observers report that the longer-term stability with the high-resolution fiber is $\sim$10 m/s.

An upgrade of the FIES fibre-shaker is being made such that you can determine what state the machine is in and see if it is running or not. This will help to make it possible to script observations with the shaker. How to use the shaker from within the sequencer and how to use the web cam that looks at the shaker was documented, while some more photos of the new fiber shaker were added.

A fundamental issue in determining the capabilities of the system and being able to assess possible improvements is to define a proper test and monitoring plan. This will establish a base-line and define the procedure to assess possible improvements. Our main priority for FIES is to implement this.