Infrared and visual lunar occultations measurements of stellar diameters and new binary stars detections at the Calar Alto 1.5m telescope

摘要

We present a program of routine lunar occultations, at optical and near-IRwavelengths, recently started at the 1.5m Spanish telescope at the Calar AltoObservatory. Both a CCD and an infrared array detector are used. The program isaimed mainly at the detection and investigation of binary systems, althoughresults in other areas of stellar research are also anticipated. Occultations are reported for a total of 40 stars. Among these, SAO 164567,SAO 78258 and AG+24 788 have been discovered to be binaries, with projectedseparations as small as 0.006". Furthermore, binarity is suspected in the caseof SAO 78119 and SAO 79251. Additionally, the angular diameter of the late-typegiant 30 Psc and of the infrared star V349 Gem have been accurately measured,this latter for the first time. We finally evaluate the instrumentation performance in terms of limitingmagnitude and angular resolution, and discuss applications to largertelescopes.