Magnetic
systems: history
€AM Her is a V~13.5 variable star which Berg & Duthie
(1977) suggested is the optical counterpart of a source in the
Uhuru catalog (also a SAS-3 source) with a period of ~3.1
hr
€Lightcurve was unlike that of other CVs: too variable for Dwarf Novae and Nova-like CVs, no eclipses
€In 1976, polarimetry obtained by Tapia, showed large circular polarisation variations on orbital period.
€Largest
circular polarisation seen in any celestial object:
hence ŚPolarą
AM
Her
Tapia (1977)