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About how massive is the black hole at the center of our Milky Way?

About 4 million times the mass of the Sun.

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  1. About 10 solar masses
  2. About 4 billion solar masses
  3. About 4 million solar masses ✔

Why: Ground-based observations show a black hole of about 4 million solar masses at our galactic center. For comparison, Cygnus X-1's black hole has about 21 solar masses.

Huh, didn't know that: The first black hole found in a binary star system is Cygnus X-1.

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The Milky Way's black hole is very central to the galaxy's plans.
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References

Answer: About 4 million solar masses. Ground-based observations show a black hole of about 4 million solar masses at our galactic center. For comparison, Cygnus X-1's black hole has about 21 solar masses.

  1. Astronomy 2e, 24.6 Evidence for Black Holes openstax.org/books/astronomy-2e/pages/24-6-evidence-for-black-holes
    a black hole in the center of our own Galaxy with a mass of about 4 million times the mass of the Sun
    Checked 2026-10-10.

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