– Astronomers discovered an isolated dwarf galaxy, PEARLSDG, about 98 million light years away, in the background of an image of other galaxies using the JWST.
– This dwarf galaxy has no neighbors and shows a lack of star-formation activity, which is unusual for a quiescent dwarf galaxy
– Dwarf galaxies contain far fewer stars than galaxies like our Milky Way, with up to 400 billion stars in the Milky Way
– The dwarf galaxy contains up to about 100 million stars, making it one of the most distant galaxies in which individual stars can be discerned
– RGB stars have a specific intrinsic brightness, allowing astronomers to measure the galaxy's distance and determine the age of its stellar population
– Despite not forming a star in at least one billion years, the dwarf galaxy displays low levels of UV energy and a very low sSFR, suggesting its star formation shut off over 1 billion years ago
– Interactions with other galaxies can cause quenching mechanisms, such as tidal stripping and other environmental effect
– These types of isolated quiescence dwarf galaxies haven't been seen before except in relatively few case
– Recent observations of large numbers of ultra-diffuse galaxies have prompted the development of new theories for galaxy formation.