
Star Orbiting Black Hole Just Confirmed a Prediction Made by General Relativity - olooney
https://www.sciencealert.com/a-star-dancing-around-a-supermassive-black-hole-is-another-win-for-relativity
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olooney
More information about S2[1]:

[1]:
[http://www.solstation.com/x-objects/s2.htm](http://www.solstation.com/x-objects/s2.htm)

It's really quite a spectacular object: a star in a highly eccentric object,
whipping past at the black hole at over 1% the speed of light, in a gravity
field so intense time dilation from curvature alone is 3%. It's a bit of
mystery why it doesn't get torn apart by tidal forces, actually, and it's
probably just barely small enough to stay together. (Because any excess mass
would have been ripped off long ago.)

They've been tracking S2 for decades (it has a 15 year orbit) but they only
now have enough data to confirm the precession.

On a historical note, the precession of mercury[2] was one of the early
puzzles/confirmations that led to widespread acceptance of general relativity.
Gravitational lensing and red-shift can be explained equally well by quasi-
Newtonian field theories, but precession is extremely difficult to explain in
flat space.

[2]:
[https://en.wikipedia.org/wiki/Tests_of_general_relativity#Pe...](https://en.wikipedia.org/wiki/Tests_of_general_relativity#Perihelion_precession_of_Mercury)

