This is the kind of stuff Gaia is doing---giving us unprecedented precise measurements so that sometimes, we find out a binary isn't quite what it seems, but rather, just close enough to *look* like one, but are actually really far apart.
Actual binary stars are gravitationally bound, dancing about each other in their mutual gravitational pull. Visual binaries, however, might not actually be binaries, but instead appear to be because of how close they appear to each other in the night sky.
Turns out Albireo, the beautiful double we always loved, one blue and one orangey red, is not an actual binary system.
This was one of our go-to night sky objects when I worked at the observatory at my undergrad institution. Everyone loved it. Including me. This is kinda disappointing, but also awesome because of what Gaia is capable of doing.
Shows just how game-changing the Gaia mission is in the world of astronomy!
And, credit for these cool tidbits about what Gaia has discovered goes to my friend @BadAstronomer, who recently sent out a tweet asking astronomers who work with the Gaia data for some juicy finds, and Albireo not being a binary is one of them!
(Thanks for letting me know you picked this one out and wrote an entire blog post on it, @BadAstronomer!)
