https://www.wolframalpha.com/input?i=entropy+of+a+black+hole+with+20+solar+masses
entropy of a black hole with 20 solar masses - Wolfram|Alpha
a black holesolar massesentropy
https://www.wolframalpha.com/input?i=Kerr+black+hole+with+12+solar+masses
Kerr black hole with 12 solar masses - Wolfram|Alpha
kerr black holesolar masses12wolframalpha
https://arxiv.org/abs/1804.02938v1
[1804.02938v1] A 3.5-million Solar Masses Black Hole in the Centre of the Ultracompact Dwarf Galaxy...
Abstract page for arXiv paper 1804.02938v1: A 3.5-million Solar Masses Black Hole in the Centre of the Ultracompact Dwarf Galaxy Fornax UCD3