Main Sections LabIR main page . ... Lunar occultations . ... An occultation of the active galaxy 3C 273 by the Moon was recorded on May 31, 2001, at the Calar Alto Observatory's 3.5m telescope using the Omega-Cass camera. More details on the use of this camera for lunar occultations, using a fast read-out mode in a subarray, was given in the case of the occultation of SAO 95190 , a first-time case for such an array. ... The occultation reappearance of 3C 273 is interesting in two respects. ...