By using guide stars astronomers are able to detect very faint celestial objects that would otherwise be invisible. This however necessitates the simultaneous observations of two stars at the same time. A system called Star Separator will add this functionality to the ESO-VLTi. In case of the Unit Telescopes of the VLT this system has to be implemented in the existing infra structure while simultaneously fulfilling many functional requirements. The major one being that each set of stars have different relative positions while the star images rotate due to the earth rotation.
About two years ago TNO Science and Industry started to design and build the Star Separators for the Auxiliary Telescopes for the ESO VLTi. Now the Unit Telescopes will also be equipped with Star Separators. Obviously the design is based on that for the Auxiliary Telescopes. However additional functionality had to be implemented to compensate for the effect of earth rotation because no de-rotator, as for the Auxiliary Telescopes, can be implemented.
The presentation will explain the functionalities of the Star Separator and how the opto-mechanical design is done.