HARPS is a new high resolution fibre-fed spectrograph dedicated to the
extremely precise measurement of stellar radial velocities. After being used for about one year including the commissioning runs we report a very successful implementation of the measures taken to maximise stability, efficiency and spectral performance. Using the Simultaneous ThAr Reference Method a short term precision of 0.2 m/s during one night and a long term precision of the order of 1 m/s have been achieved. Equipped with a fully automated data reduction pipeline that produces solar system barycentric radial velocities in near real-time, HARPS promises to deliver data of unequalled quality. HARPS will primarily be used for the search for exoplanets and in the field of asteroseismology. First exciting scientific results confirm these expectations.
Optical fibres have been extensively used at ESO to link telescopes to spectrographs. The last two developments included the preparation of the fibres for the HARPS and FEROS instruments in La Silla Observatory. The HARPS fibre bundle uses a high efficient scrambler for precise measurements of radial velocities (< 1 m/s). The FEROS fibre micro-lenses were updated to match the 2.2 m telescope with emphasis in optimizing the efficiency. This paper describes the features and performances of these fibres.
The high-resolution spectrograph HARPS (High-Accuracy Radial-velocity
Planet Searcher) will be installed on the 3.6m telescope at the ESO La Silla Observatory towards the end of 2002 and offered to the astronomical community by mid-2003. Assembly and integration of the instrument took place at the Geneva Observatory, Switzerland, during Spring 2002. At present, the verification of the system performance is in progress and is already in an advanced phase. We present in this paper the first results of our laboratory tests and describe various performance figures. We stress the outstanding mechanical and thermal stability of the instrument which are crucial for accurate radial velocity measurements. We also give a description of the simultaneous ThAr-reference technique which ensures an overall efficiency 6 times higher than with an the iodine cell absorption
The combination of the high instrumental stability with the simultaneous ThAr-reference technique provides HARPS with characteristics highly adapted for accurate radial-velocity determination at the level of 1 ms<sup>-1</sup>. These make our instrument suitable for the detection of planetary systems and of extra-solar planets with sub-saturnian mass.