Close together or far apart?

https://www.legacysurvey.org//viewer/?ra=37.7662&dec=-7.3371&layer=ls-dr9&zoom=16
images like this make me wonder if they are colliding, or just in overlapping in the field of view. i hope one day we will have 3D mapped the sky to end this problem :laughing:

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It’s funny you should mention 3d mapping, because with parallax measurements, we have pretty much done that. These 2 stars have parallaxes within errors of eachother, and very similar proper motions, so i’m very confident in saying they’re gravitationally bound. You’ll find that binary systems are pretty common.

One thing to note though is that stars are extremely luminous. They always look much bigger than they actually are. So they definitely arent colliding. Stars can touch eachother in systems called contact binaries, but they would be so close to eachother, that we wouldn’t be able to resolve them from earth.