Charting the galaxy: Milky Way Mapper survey releases latest all-sky spectra

The Sloan Digital Sky Survey V (SDSS-V) has released its 20th public data set (DR20), significantly expanding the Milky Way Mapper (MWM) survey. This comprehensive spectroscopic map reveals the properties of stars within and around the Milky Way, with over 2 million spectra captured through repeat visits. With data spanning both the northern and southern skies, the dataset enables astronomers to study stellar populations, chemical compositions, and motion across the galaxy.

The release includes the first major public dataset from the MWM Halo Program, mapping the faint stellar shroud enveloping the Milky Way's disk. This ancient stellar population preserves a fossil record of the galaxy's formation and history of engulfing smaller satellite galaxies. Among the release's highlights are over 49,000 new white dwarf spectra, many of which bear signatures of remnant planetary systems.

Additionally, the Solar Neighborhood Census builds the most complete spectroscopic map to date of objects within 250 parsecs of the sun, focusing on low-mass M dwarfs and brown dwarfs. By combining SDSS-V spectroscopy with precise distances from the ESA's Gaia satellite, astronomers now have a new benchmark dataset for understanding stellar mass, age, and composition in our cosmic backyard.