We report on how the recent numerical solution of the problem of a hydrogen atom in a magnetic field of arbitrary strength ‐one of the remaining ’unsolved elementary problems in atomic physics’ (Kleppner et al.) ‐has helped in identifying the mysterious line features unexplained for almost five decades in the optical spectrum of the white dwarf star Grw+70°8247 as due to hydrogen atoms exposed to a magnetic field of ∼320 million Gauss, and, at the same time, has laid the foundation for the quantitative spectroscopy of these compact cosmic objects in the magnetic field range up to ∼103 Megagauss.