Meet ZTF J1901+1458 — the Smallest, Densest White Dwarf Ever Seen

James Maynard
Jul 2 · 4 min read

A dwarf star the size of our Moon is the smallest — yet most-massive — such body ever seen by astronomers. And, it may be about to collapse.

A simulation showing what the white dwarf ZTF J1901+1458 might look like, relative to the size of the Moon. Image credit: The Cosmic Companion/Simulation created in Universe Sandbox.

White dwarfs are the collapsed remains of dead stars about as massive as the Sun. Following the loss of significant amounts of mass during their death throes, these stellar corpses typically settle down to bodies…