  Six decades and counting, the formation of hot ~20,000-30,000 K Extreme
Horizontal Branch (EHB) stars in Galactic Globular Clusters remains one of the
most elusive quests in stellar evolutionary theory. Here we report on two
discoveries shattering their currently alleged stable luminosity. The first EHB
variability is periodic and cannot be ascribed to binary evolution nor
pulsation. Instead, we here attribute it to the presence of magnetic spots:
superficial chemical inhomogeneities whose projected rotation induces the
variability. The second EHB variability is aperiodic and manifests itself on
time-scales of years. In two cases, the six-year light curves display
superflare events a mammoth several million times more energetic than solar
analogs. We advocate a scenario where the two spectacular EHB variability
phenomena are different manifestations of diffuse, dynamo-generated, weak
magnetic fields. Ubiquitous magnetic fields, therefore, force an admittance
into the intricate matrix governing the formation of all EHBs, and traverse to
their Galactic field counterparts. The bigger picture is one where our
conclusions bridge similar variability/magnetism phenomena in all
radiative-enveloped stars: young main-sequence stars, old EHBs and defunct
white dwarfs.
