Jonathan O'Callaghan

Contributing Writer

An abstract black ball on a blue background.
Abstractions blog

In Violation of Einstein, Black Holes Might Have ‘Hair’

February 11, 2021

A new study shows that extreme black holes could break the famous “no-hair” theorem, and in a way that we could detect.

Historical star chart of the constellation Monoceros.
Abstractions blog

‘Unicorn’ Discovery Points to a New Population of Black Holes

January 27, 2021

Small black holes were nowhere to be found, leading astronomers to wonder if they didn’t exist at all. Now a series of findings, including a “unicorn” black hole, has raised hopes of solving the decade-long mystery.

About the author

Jonathan O'Callaghan is a freelance space and science journalist based in London. He writes regularly for a number of publications including The New York Times, Scientific American, New Scientist, Forbes and Wired. You can read more of his work or get in contact at, or find him on Twitter @Astro_Jonny.