Nautilus - How to recognize a black hole
I wrote a blog for Nautilus Magazine's Identity issue on how the classification system for galaxies with supermassive black holes leaves a lot to be desired.
Astronomers can sometimes be literal to a fault. We like to call things as we see them. For example, if it’s red and it’s huge: “Red Giant.” White and small: “White Dwarf.” Massive explosion: “Big Bang.” Dark and sucks everything in: “Black Hole.” Most of the time, classifying objects this way works fine—either it’s new, or it’s something we already know of. But sometimes, as with Pluto, we make new observations that force us to question the name, reassess the object, and identify it differently. You might think this never happens with something as clearly defined as a black hole, but you’d be wrong.
Read the full article here.