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MAST Staff - 2025 Oct 29SDSS Legacy Spectra Data Now Available at MAST
The SDSS Legacy Archive at MAST (SLAM) now includes data from the SDSS Legacy Spectra Survey, the SDSS Supernova Survey, and the SDSS Extension for Galactic Understanding and Evolution (SEGUE)!
The SDSS Legacy Archive at MAST (SLAM) is a partnership between the Sloan Digital Sky Survey (SDSS-V) collaboration and MAST, which will host a copy of all science-ready images, spectra, and catalogs across all public SDSS data releases through SDSS-V. Data from other SDSS surveys including MaNGA and APOGEE , and eBOSS, and Legacy Imaging have been available at MAST for a few months.
Now, SDSS Legacy Spectra data has been added to SLAM! The SDSS Legacy Spectra Survey is an optical-wavelength spectroscopic survey of millions of stars, galaxies, and quasars. This includes data from the original SDSS Legacy Spectra survey which targeted galaxies and quasars to map the large-scale structure of the Universe, the SDSS Supernova Survey observing time series of supernovae through repeat observations, and the Sloan Extension for Galactic Understanding and Exploration (SEGUE) which targeted stars in the Milky Way with a goal of mapping the out the galactic disk in abundance space. Together, the SDSS Legacy Spectra and SEGUE extension collected data between the years of 2000-2009 as part of the SDSS-I, -II, and -III projects. A summary SDSS data products available at MAST can be found in the SDSS Legacy Archive at MAST User Manual.
Data Access
The SDSS Legacy Archive at MAST User Manual describes how to search for and download SDSS data using MAST interfaces. SDSS data can be accessed at MAST in-browser using the MAST Portal or in Python using astroquery.mast. Search for Mission="SDSS" to view all SDSS data, or use the "Provenance Name" field to search for specific SDSS surveys (for example, "SDSS Legacy Spectra" or "SEGUE"). There are also a few Jupyter Notebook tutorials available which demonstrate how to access SDSS data through MAST.
All released SDSS data, including the raw data and pre-science data products, still remain available through the SDSS-provided services including the Science Archive Server (SAS) and Catalog Archive Server (CAS). The copies hosted at MAST provide an additional entry point to discovering and accessing the data, and provide all of the advantages of a multi-mission archive: SDSS data is now available through the same interfaces as HST, JWST, TESS, Pan-STARRS, and Gaia holdings, opening up new opportunities for scientific synergies between missions.
New Tutorial Notebooks
In addition to the new data, two new SLAM tutorial notebooks are now available!
- Galaxy Morphology with SDSS and Astrocut : This notebook shows how to use Astrocut to create image cutouts with SDSS data explore galaxy morphology by creating a Hubble Tuning Fork Diagram.
- Stellar Classification with SEGUE: This notebook demonstrates how to search for and download SDSS Legacy Spectra data from MAST, plotting spectra for different classifications of stars from the SEGUE survey.
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