5.3.3 Observing Mode: Bright Object

For very bright objects, where the estimated on-source exposure time per map position is 15 s or less, the total observing time is dominated by telescope moves. The efficiency of mapping such bright objects can be improved by observing two map positions and one off-position per nod-cycle using an asymmetric chop. In this mode, the total overhead is 3 N ton + 300 s assuming an on-source exposure times per map position of about 15 s. Please contact the SOFIA Help-Desk, if you are planning shorter integration times. The overhead increases with shorter integration times and the standard overhead calculation should be overwritten with the actual overheads for such short integrations times.