I was staring at the Gal Map & thinking about what else we know:
* the UA are being delivered (likely) somewhere in the bubble
* we've found the convoys toward the outside of the bubble (Timocani & 109 Virginis)
* we've found free-floating UAs in the Pleiades (maybe natural spot, maybe not)
* we've seen the UA in the Wings trailer in the California nebula, headed bubble-ward
Probably stupid, but if you draw that line in order outward, you almost directly hit the "Trifid of the North" nebula. And it too has a line of the 2MASS stars next to it. In addition, "Trifid of the North Sector HR-W D1-8" has a big Class A star & seems to be the closest star to the nebula (none directly in it that I can find). 2.6K Ly out. Maybe, if all else fails, we should check there to see if there's anything there (SSS, PoI, whatever).
Pics:
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