Medium-size black holes are much less massive than the supermassive black holes, which are up to billions of solar masses and reside in the centers of large galaxies.

• 中等大小的黑洞比超大黑洞的质量要小很多，超大黑洞的质量可以达到数十亿个太阳系质量，兵存在于更大的星系中。