Ancient dwarf galaxy Loki is found buried inside the Milky Way
Updated
Updated · Futurism · May 3
Ancient dwarf galaxy Loki is found buried inside the Milky Way
11 articles · Updated · Futurism · May 3
Researchers studied 20 metal-poor stars in the Milky Way's galactic plane, finding 11 prograde and nine retrograde orbits that point to an early merger.
Their chemistry showed signatures of supernovas and neutron star mergers but no white dwarf explosions, suggesting Loki was a short-lived dwarf galaxy consumed billions of years ago.
Loki was found hiding in plain sight. How many more ghost galaxies are lurking undiscovered inside the Milky Way?
How does finding a galactic corpse in our backyard challenge our fundamental theories of dark matter?
Discovery of Loki: Identifying 20 Ancient Stars from a Massive Dwarf Galaxy Merger Embedded in the Milky Way Disk
Overview
Astronomers discovered 20 ancient, metal-poor stars embedded within the Milky Way's disk, remnants of a dwarf galaxy named Loki that merged with our galaxy over 10 billion years ago. These stars share a unique chemical fingerprint dominated by massive star explosions and neutron star mergers, with a notable absence of elements from white dwarf supernovae, indicating a short, intense burst of star formation. Loki's substantial mass allowed it to retain and mix these elements, resulting in exceptional chemical uniformity. The stars' unusual mix of prograde and retrograde, highly eccentric orbits within the disk challenges traditional galaxy formation models, revealing that early massive mergers shaped the Milky Way's disk. Future surveys aim to find more such hidden remnants and refine our understanding of galactic assembly.