High precision imaging photometry of bright sources with the JWST Mid-Infrared Instrument (MIRI), such as time-series observations (TSOs), may require target acquisition to ensure repeatable measurements.
Target acquisition for MIRI imaging currently unsupported
The MIRI imager can be used to obtain high precision photometry of bright sources that may be useful for time-series observations (TSOs). Given the high stability and photometric precision required for such observations, target acquisition (TA) is usually recommended to ensure that the target is very accurately placed in the nominal pointing position for the required subarray. This is particularly important for repeated observations, where different exposures will be combined.
While TSOs are supported for MIRI imaging, TA for MIRI imaging is not currently supported, so proposers should assess the importance of TA for their observations. TA for MIRI imaging will become available in future cycles.