In a lot of ways, astronomy is nothing more than the study of how mass keeps getting redistributed over the history of the universe, and it is in the surprising ways that mass congregates that some of the most interesting stuff is found. Back when I was in grad school, it was discovered that, more or less, the orbits of stars in the bulgy parts of galaxies are directly related to the size of the supermassive black holes they contain.

But then, every once in a while, a system comes along and refuses to follow any rules.

In studying the nearby dwarf galaxy Leo I, researchers from the University of Texas recently discovered a black hole nearly the same size as the one in the core of the Milky Way. The bulgy bits of Leo I are a lot smaller than the bulgy bits of our galaxy, and the two should not have similar-sized black holes. Research lead María José Bustamante states simply: …there is no explanation for this kind of black hole in dwarf spheroidal galaxies.

This work is published in The Astrophysical Journal and is going to force folks to spend the next many years trying to figure out how in the Universe this can happen. The Universe really is more creative than we are in what it figures out how to do.

More Information

McDonald Observatory press release

“Dynamical Analysis of the Dark Matter and Central Black Hole Mass in the Dwarf Spheroidal Leo I,” M. J. Bustamante-Rosell et al., 5 November 2021, The Astrophysical Journal