The STELLA robotic observatory: first two years of high-resolution spectroscopy

The STELLA project consists of two robotic 1.2m telescopes to simultaneously monitor stellar activity with a high resolution echelle spectrograph on one telescope, and a photometric imaging instrument on the other telescope. The STELLA observatory is located at the Observatorio del Teide on the Canary island of Tenerife. The STELLA Echelle spectrograph (SES) has been operated in robotic mode for two years now, and produced approximately 10,000 spectra of the entire optical range between 390 and 900nm at a spectral resolution of 55,000 with a peak shutter-open time of 93%. Although we do not use an iodine cell nor an actively stabilized chamber, its average radial velocity precision over the past two years was 60 to 150 m/s rms, depending on target. The Wide-Field STELLA Imaging Photometer (WIFSIP) is currently being tested and will enter operation early 2009. In this paper, we present an update report on the first two years of operation.