BULLETIN
Fossil galaxy lies near Andromeda
A relic of one of the first ever galaxies has been discovered on the outer fringes of the Andromeda Galaxy.
The galaxy, called Pegasus V, was detected during the DESI Legacy Imaging Survey, a systematic search of Andromeda’s dwarfs, but it was eagle-eyed amateur astronomer Giuseppe Donatiello that spotted a strange smudge in one of the images. Follow-up observations revealed this was a faint galaxy.
The stars of Pegasus V lack heavy elements, suggesting they first formed in the very early Universe, before later generations of stars seeded the cosmos with more elements.
“This discovery marks the first time a galaxy this faint has been found around the Andromeda Galaxy using an astronomical survey that wasn’t specifically designed for the task,” says Michelle Collins from the University of Surrey, who led the research. “We hope that further study of Pegasus V’s chemical properties will provide clues into the earliest periods of star formation in the Universe. This little fossil galaxy from the early Universe may help us understand how galaxies form and whether our understanding of dark matter is correct.” www.legacysurvey.org