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The new cataclysmic variable RX J1554.2+2721 in the period gap

G. H. Tovmassian·J. Greiner·S. V. Zharikov·J. Echevarria·A. Kniazev
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Abstract

We report on the results of a spectroscopic and photometric study of a new cataclysmic variable, identified as optical counterpart of the X-ray source RX J1554.2+2721 detected by ROSAT. The spectroscopic observations of the relatively bright (~16.5mag) object show systematic radial velocity variations with a semi-amplitude of ~140 km/sec. Besides the clear presence of distinct low and high states there are periodic photometric light variations with an amplitude of about 0.15 magnitude in the R band. The orbital period is 2.753h thus being within the period gap, at its upper border. The flux distribution in the spectrum of the object shows a substantial contribution of a M4V secondary, and also bears clear signs of cyclotron emission. Thus, we classify the discovered object as a new member of the AM Her class of magnetic cataclysmic variables. This classification is further supported by the soft X-ray spectrum, the characteristic profiles of the emission lines, the tomography map and the shape of the orbital light curve. A simple fitting of the spectrum in the low and high states suggests a reduced mass transfer rate in RX J1554.2+2721, compared to similar objects outside the period gap.

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G. H. Tovmassian, J. Greiner, S. V. Zharikov, J. Echevarria, A. Kniazev. 2001-10-02. The new cataclysmic variable RX J1554.2+2721 in the period gap. https://doi.org/10.1051/0004-6361%3A20011434

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