[LibWhacker]

Oh, that's it, thank you! I thought I was losing my mind. Obviously, stars orbiting Sgr A* up close and personal don't take 250M years go around it.

But I wonder if this new finding is going to tell them anything about dark matter that they didn't know before? I mean, it seems like it's a pretty significant discovery... The outer regions of every disk galaxy rotating once every billion years, regardless of mass, etc. Really bizarre.

[Moonman62]

I don’t think it’s all that unexpected. My unscientific feeling is this just confirms what they already know, dark matter dominates. And the outer bands only contain a small amount of the mass in a galaxy. Notice in my graphic that the measurement uses hydrogen gas for the outer bands.

I think the value of this new finding is represented by this statement:

“This is an important result because knowing where a galaxy ends means we astronomers can limit our observations and not waste time, effort, and computer processing power on studying data from beyond that point,” said Meurer.