The James Webb Space Telescope has identified a dwarf galaxy that should not exist: it is isolated and quiescent, because it does not interact with nearby galaxies or produce new stars.
This is a very rare type, of which few other examples are known, and could change current knowledge regarding the formation and evolution of galaxies.
This is indicated by the study published in Astrophysical Journal Letters and coordinated by Arizona State University.
The unusual galaxy was called Pearlsdg because it appeared surprisingly in the images taken as part of the Pearls (Prime Extragalactic Areas for Reionization and Lensing Science) project conducted by the James Webb telescope managed by the space agencies of the United States, Europe and Canada.
Dwarf galaxies (which have fewer than 100 million stars) are the most common in the universe, but Pearlsdg immediately appeared unique in its kind, because unlike the others it does not interact with nearby galaxies and, despite being isolated, it does not produces new stars.
“Such quiescent, isolated dwarf galaxies have never been seen before, except in a few cases,” notes the study's first author, Tim Carleton.
“They are not expected to actually exist, given our current understanding of the evolution of galaxies, so the fact that we see this object helps improve our theories of galaxy formation.”
Surprisingly, the images taken by the James Webb telescope made it possible to observe individual stars in the galaxy, which is one of the most distant for which a similar level of detail is possible.
The brightness of the stars has allowed astronomers to estimate their distance, which is approximately 98 million light years.
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