why does astrophysics still use ergs
Various astrophyicists are hardwired by early adoption to to use CGS electromagnetic units and don't feel obliged to follow no union rules . . . no one rejects their papers over units, so <shrug>.
A foe is a unit of energy equal to 1044 joules or 1051 ergs, used to express the large amount of energy released by a supernova.[1] An acronym for "[ten to the power of] fifty-one ergs",[2] the term was introduced by Gerald E. Brown of Stony Brook University in his work with Hans Bethe, because "it came up often enough in our work".[3]
(although my postdoctoral advisor claimed our weird units were intended to keep the physicists at bay.)