Related papers: HS 0943+1404, a true intermediate polar
Some of the white dwarfs exhibit among the strongest magnetic fields in the universe. Many of these degenerate magnetic stars are also rotating very slowly. Among these objects, Grw+70$^\circ$\,8247, with its century-long suspected rotation…
We present radial velocity observations of four extremely low-mass (0.2 Msol) white dwarfs. All four stars show peak-to-peak radial velocity variations of 540 - 710 km/s with 1.0 - 5.9 hr periods. The optical photometry rules out…
Intermediate Polars (IPs) are a group of cataclysmic variables (CVs) which are thought to contain white dwarfs which have a magnetic field strength in the range ~0.1-10MG. A significant fraction of the X-ray sources detected in recent deep…
SDSS J080434.20+510349.2 is the WZ type binary that displayed rare outburst in 2006 (Pavlenko et al., 2007). During the long-lasting tail of the late stage of the outburst binary shown the two-humped or four-humped profile of the orbital…
We report on high time resolution, high signal/noise, photo-polarimetry of the intermediate polars NY Lup and IGRJ1509-6649. Our observations confirm the detection and colour dependence of circular polarization from NY Lup and additionally…
We present fast timing photometric observations of the intermediate polar V2069 Cygni (RX J2123.7+4217) using the Optical Timing Analyzer (OPTIMA) at the 1.3 m telescope of Skinakas Observatory. The optical (450-950 nm) light curve of V2069…
PSR J0636+5128 is a millisecond pulsar in one of the most compact pulsar binaries known, with a 96\,min orbital period. The pulsar mass function suggests a very low-mass companion, similar to that seen in so-called "black widow" binaries.…
We present VLT and Magellan spectroscopy and NTT photometry of nine faint cataclysmic variables (CVs) which were spectroscopically identified by the SDSS. We measure orbital periods for five of these from the velocity variations of the…
We present the results of optical identification of two X-ray sources from RXTE and INTEGRAL all sky surveys: XSS J00564+4548 and IGR J00234+6141. Using the optical data from Russian-Turkish 1.5-m Telescope (RTT150) and SWIFT X-ray…
Previous optical and radio observations of the binary millisecond pulsar PSR J1640+2224 have come to inconsistent conclusions about the identity of its companion, with some observations suggesting the companion is a low-mass helium-core…
We report the discovery of the ultracompact hot subdwarf (sdOB) binary OW J074106.0-294811.0 with an orbital period of P$_{\rm orb}=44.66279\pm1.16\times10^{-4}$ min, making it the most compact hot subdwarf binary known. Spectroscopic…
PSRJ1910-5959A (J1910A) is a binary millisecond pulsar in a 0.837 day circular orbit around a helium white dwarf (HeWD) companion. This pulsar is located 6.3 arcmin away from the centre of the globular cluster NGC6752. Given the large…
Binary systems consisting of a white dwarf and a main-sequence companion with orbital periods up to $\approx 100$ d are often thought to be formed through common envelope evolution which is still poorly understood. To provide new…
We present the spectroscopic orbit of LHS 1610A, a newly discovered single-lined spectroscopic binary with a trigonometric distance placing it at 9.9 pm 0.2 pc. We obtained spectra with the TRES instrument on the 1.5m Tillinghast Reflector…
We report the discovery of PSR J1909-3744, a 2.95 millisecond pulsar in a nearly circular 1.53 day orbit. Its narrow pulse width of 43 microseconds allows pulse arrival times to be determined with great accuracy. We have spectroscopically…
We present the results of our optical identification of the X-ray source IGR J16547-1916 detected by the INTEGRAL observatory during a deep all-sky survey. Analysis of the spectroscopic data from the SWIFT and INTEGRAL observatories in the…
PSR J1905+0154A is a binary millisecond pulsar located in the globular cluster (GC) NGC 6749. It was discovered in 2004 in a search for pulsars in GCs carried out with the Arecibo 305-m radio telescope. The pulsar has a spin period of 3.2…
We report on the discovery of a new X-ray pulsator, Swift J201424.9+152930 (Sw J2014). Owing to its X-ray modulation at 491 s, it was discovered in a systematic search for coherent signals in the archival data of the Swift X-ray Telescope.…
The cataclysmic variable SDSSJ 015543.40+002807.2 is confirmed to be a magnetic system of the AM Herculis type. With an orbital period of 87.13 min, it is also the shortest-period eclipsing Polar known. Monitoring with XMM-Newton finds a…
Aims. We intend to establish the X-ray properties of Swift J0732.5-1331 and therefore confirm its status as an intermediate polar. Method. We analysed 36,240 s of X-ray data from RXTE. Frequency analysis was used to constrain temporal…