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Physics, Astronomy & Cosmology / Re: Orbiting or descending into the black hole at the centre of the Milky Way?
« on: 28/11/2022 16:30:16 »Quote from: bored chemistMainly the MW is in orbit around itself.And the mass of the Milky way is dominated by the (so far) invisible Dark Matter halo.
Though a great bit of that halo extends beyond the Galactic disk, and thus, due to the shell theorem, has no effect on the stars' orbits around the Sun. Only that DM at a lesser distance from the center than the star is question would.
So for the Sun, DM has an effect on its orbit, but doesn't dominate, as the DM closer to the center than we are, while a significant fraction of the total mass affecting our orbit, it isn't the majority of it.
If you look at the predicted and observed rotation curves here:
https://www.astronomy.ohio-state.edu/thompson.1847/1101/RotCurve2.gif
Note that close in to the center, you see little to no difference, as the mass of visible matter heavily dominates there. You don't see the deviation until you get out of the central bulge region and into the disk.