Optical/infrared spectroscopy and photometry of the short-period binary RX J1914+24

Abstract

We present observations of the proposed double-degenerate polar RX J1914+24. Our optical and infrared spectra show no emission lines. This, coupled with the lack of significant levels of polarization, provides difficulties for a double-degenerate polar interpretation. Although we still regard the double-degenerate polar model as feasible, we have explored alternative scenarios for RX J1914+24. These include a double-degenerate Algol system, a neutron star–white dwarf pair and an electrically powered system. The latter model is particularly attractive since it accounts naturally for the lack of both emission lines and detectable polarization in RX J1914+24. The observed X-ray luminosity is consistent with the predicted power output. If true, then RX J1914+24 would be the first known stellar binary system radiating largely by electrical energy.