The Milky Way's quiet, introverted monster won't spin

[Admin]

This supermassive black hole's spin has been measured for the first time, and it's surprisingly low.

The Milky Way's quiet, introverted monster won't spin : Read more

 

[rod]

Interesting report, the paper cited too. 'An Upper Limit on the Spin of SgrA* Based on Stellar Orbits in Its Vicinity, https://iopscience.iop.org/article/10.3847/2041-8213/abb9b4', "Abstract The spin of the massive black hole (BH) at the center of the Milky Way, SgrA*, has been poorly constrained so far. We place an upper limit on the spin of SgrA* based on the spatial distribution of the S-stars, which are arranged in two almost edge-on disks that are located at a position angle of approximately ±45° with respect to the Galactic plane, on a milliparsec scale around the Galactic center. Requiring that the frame-dragging precession has not had enough time to make the S-star orbital angular momentum precess, the spin of the massive BH at the center of the Milky Way can be constrained to χ lesssim <~ 0.1."

My observation. Using 4.15E+6 solar mass BH, diameter ~ 1.6385E-1 AU. The abstract says "on a milliparsec scale", ~ 206 AU for 1E-3 pc. Sgr A* distance ~ 8000 pc.