Topic: Milky Way

Fraser Cain and Pamela L. Gay examine possible futures of the universe across vastly different timescales. Topics include the Milky Way and Andromeda, cosmic isolation as expansion continues, the fading microwave background, the end of star formation and the era of stellar remnants. They discuss uncertain processes such as proton decay, black-hole evaporation through Hawking radiation, entropy and heat death, alongside alternative outcomes if dark energy evolves. These are model-dependent projections. Pamela Gay is a senior scientist at the Planetary Science Institute. Published on 21 Septembe

Subha Majumdar presents a six-dimensional Milky Way phase-space catalogue designed to map stellar motions and dark matter beyond the reach of Gaia parallaxes alone. Gaia astrometry is combined with spectrophotometric distances and radial velocities from fourteen surveys, including DESI, SDSS-BOSS, APOGEE and LAMOST. The resulting catalogue contains about 33 million tracers and detailed distance–velocity measurements for roughly half a million halo stars. It characterizes distant clusters, dwarf galaxies and stellar streams, enabling mass modeling, kinematic studies, abundance mapping, Galactic