A milestone for MilkyWay@home - Measuring dark matter in a tidal stream of stars

This video accompanies the press release “Ancient Dwarf Galaxy Reconstructed with MilkyWay@home Volunteer Computer,“ (links and high resolution image can be found at ~newbeh/) announcing the publication of The Astrophysical Journal paper “Estimate of the Mass and Radial Profile of the Orphan–Chenab Streamʼs Dwarf-galaxy Progenitor Using MilkyWay@home,“ by Eric J. Mendelsohn, Heidi Jo Newberg, Siddhartha Shelton, Lawrence M. Widrow, Jeffery M. Thompson, and Carl J. Grillmair, February 17, 2022. Prof. Heidi Jo Newberg explains how the MilkyWay@home volunteer supercomputer was used to determine the shape and dark matter content of the ultrafaint dwarf galaxy that fell into the Milky Way three billion years ago and was ripped apart to form the Orphan-Chenab Stream (OCS). The measured dark matter mass is ten times less than that of dwarf galaxies observed today. This could mean that ultrafaint dwarf galaxy masses are overestimated, or that dwarf galaxies that were ripped apart billions of