[Placidus (Mike and Trish)]

Originally Posted by AdamJL

what made that "gap" in the main galaxy? Fascinating.

Love seeing the detail in the smaller galaxies. This was a nice view, thanks for sharing.

Thanks Adam. Here is a paper that explains the 'gap' or 'void' as being due to a persistent lack of recent star formation. There are only cool old stars there. The paper says the void is consistent with the effects of a dark-matter subhalo. Wikipedia says a subhalo is a semi-independent chunk of dark matter orbiting within the galaxy.