# Possible origins of the Antlia 2 galaxy?

At $$32.3\,{\rm mag}\,{\rm arcsec}^{-2}$$, the Antlia II dwarf galaxy is the most diffuse galaxy ever observed in terms of surface brightness. It was only discovered by pre-selecting stars based on their proper motions as measured by the Gaia mission:

The discovery article includes a discussion of possible origins, but ultimately states caveats to all proposed scenarios. How could such an extreme galaxy come to exist?