The new cataclysmic variable RX J1554.2+2721 in the period gap
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 (16.5') object show systematic radial velocity variations with a semi-amplitude of ~140 km s-1. Besides the clear presence of distinct low and high states there are periodic photometric light variations with an amplitude of about 0.15 mag in the R band. The orbital period is 2.753 hours 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 M4 V 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.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- December 2001
- DOI:
- 10.1051/0004-6361:20011434
- arXiv:
- arXiv:astro-ph/0110048
- Bibcode:
- 2001A&A...380..504T
- Keywords:
-
- STARS: INDIVIDUAL: RX J1554.2+2721;
- STARS: NOVAE;
- CATACLYSMIC VARIABLES;
- STARS: BINARIES: CLOSE;
- X-RAYS: STARS;
- Astrophysics
- E-Print:
- 11 pages, 11 figures, accepted in A&