AM Herculis


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AM Herculis

(her-kyŭ-liss) The archetypal magnetic white dwarf binary system, or polar, identified in 1976 from an Uhuru X-ray source. Optically it is a faint variable binary star (mag. 12–15), exhibiting strong optical polarization and a photometric period of 185 minutes. X-ray emission is strongly modulated at the same period, due to rotation of the white dwarf. The characteristic high XUV-to-optical luminosity ratio has led to several other similar systems being found from X-ray and XUV surveys. See magnetic cataclysmic variables.
References in periodicals archive ?
17) Thomas & Steiman-Cameron, 'V2301 Ophiuchi: An X-ray bright eclipsing AM Herculis object', ApJ.
Their main contention and they key to their theory is that Nova Cygni 1975 happened in an AM Herculis system, a binary star in which a cool normal star and a highly magnetized white dwarf star are bound together by gravity.
Stockman told SCIENCE NEWS that they can't calculate a value for the field but they estimate it as strong enough to assign the nova to an AM Herculis system.
Spectra indicate the source to be of the AM Herculis type, in which a white dwarf spins in synchronism with its orbital period around a massive companion.