Data Release 5b

November 15, 2022

ULLYSES Data Release 5b (DR5b) consists of high-level science products (HLSPs) for 17 new ULLYSES low-mass targets. Data releases typically include reprocessed HLSPs from previous releases, but DR5b is limited to only new products for these 17 T Tauri stars. In addition, a new MAST search form that provides ULLYSES data, stellar parameters, and observational information is now available. This new search form will be the main platform to query and download ULLYSES data going forward.

DR5b Target Breakdown

The DR5b target sample is limited to the remaining 17 survey T Tauri stars that were observed too late to be included in DR5 (June 2022). It is important to be aware of some limitations to the products, listed below:

ULLYSES Search Form

The ULLYSES team, in partnership with MAST (Mikulski Archive for Space Telescopes), is proud to announce the release of a new ULLYSES search form. This search form supports querying targets and datasets based on both observational and astrophysical parameters, a key functionality given the multi-dimensionality of the parameter space covered by ULLYSES targets. In addition to specialized search parameters, the new form also features direct file downloads and customized API script generation. The search form, which follows the format of the new HST search form, is fully integrated in MAST to ensure long-term maintainability and legacy.

Some highlights of the new ULLYSES search form are: Products and their contributing data were previously hosted on the ULLYSES website, but these have now been removed. To download HLSPs only, the new MAST search form should be used. To download HLSPs and their contributing data, the MAST Data Discovery Portal should be used by following these instructions. If you have any feedback or questions on using the new ULLYSES search form, feel free to reach out through the Archive Help Desk or send an email to

DR5b Caveats and Known Issues

Caveats for DR5b data only are listed below. For a complete list of caveats for all other data, please see the DR5 notes.

Data Description & Download

A full description of the ULLYSES data products and how they are created can be found here. Data may be downloaded from the ULLYSES search form (HLSPs only), the MAST Data Discovery Portal (HLSPs and their contributing data), or directly as a High-Level Science Product collection using the DOI.


A description of the ULLYSES observations and data products is given in:

For more information on how to cite ULLYSES data, see ULLYSES References.

Charting young stars’ ultraviolet light with Hubble.

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