Instrument Names as They Appear in MAST

The names of the JWST science instruments as viewed in MAST have been supplemented with configuration information. This change enables you to target more precisely your Advanced Searches in the Portal, and Observations.query_criteria() searches with the astroquery.mast API, compared to using the instrument name alone. It also makes the instrument search criteria more similar to that for HST.

The standard JWST instrument names are listed in the headings of the table below, and the possible Instrument name+configuration variants are given in succeeding rows. Data from FGS are also searchable, but this instrument name has not been augmented.





Affected Queries

The affected search types are described below. Use a wildcard character (either the asterisk or the percent symbol: * or %) in the instrument name where needed.

Updates in progress

Software to extend the instrument names was installed at the beginning of 2023 March, but the results will not be fully realized until all JWST data in the archive have been reprocessed. This mixed-state of old and new conventions is likely to persist through early April. Until then we recommend using a wildcard at the end of an instrument name to be certain of searching for all data for that instrument.

Portal Advanced Search

When constructing a Portal Advanced Search, follow the instructions below if you wish to include an instrument name among your search criteria.

1Choose 'JWST' in the Mission filter.

Either check the box for one or more of the fully qualified instrument names/configurations from the table above...


...or type the simple instrument name in the dialog box, followed by a single wildcard character to select all configurations.

Only one wildcard may be used in any given filter.

API Search

Specify the instrument criteria among your astroquery.mast query parameters; example values are given below:

matched_obs = Observations.query_criteria(
    'obs_collection': 'JWST',
    'instrument_name': ['NIRISS/IMAGE', 'MIRI*']

Other Queries

Most MAST query types for JWST data work as before, i.e., there has been no change. Specifically searches of the following collections are not affected:

  • MAST Observations by Observation ID
  • MAST Observations by Proposal ID
  • JWST Instrument Keywords
  • Observations in a DOI (and the interface for creating a DOI)

Data Use | Acknowledgements | DOI | Privacy

Send comments & corrections on this MAST document to: