NASA Exoplanet Science Institute
KI Nuller Sensitivity and Observing parameters

Update for 2011A: Proposals for the nuller will be accepted, but availability of this instrument in future semesters is not guaranteed.

The sensitivities given below are the current performance levels. These sensitivity values are based on past interferometer performance in good weather. Note that the interferometer performance degrades in poor seeing.

In the Nuller mode the main data product is the coherent null leakage for a given source. The null leakage is related to the visibility as N = (1-V)/(1+V) which in the limit of small N, approximates to V2 = 1 - 4N for the squared visibility (the normal KI visibility measurement). Integrations on the target source and calibrators are interleaved in time. Each integration includes all local (detector, background) calibrations. See the KI nulling description for more details on the nulling observations and how these observations can be used for measuring visibilities.

Observations with the nuller mode can only be combined with the K/L split pupil mode within a single night. See the configuration page for more details.

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