Related papers: Monitoring the spin up in RX J0806+15

We have carried out high-precision timing observations of the eclipsing binary PSR J2051-0827 in the 3.3 years since its discovery. These data indicate that the orbital period is decreasing at a rate of dPb/dt = (-11+-1)X10^-12. If secular,…

We carried out optical observations of the field of the X-ray pulsator RXJ0806.3+1527. A blue V=21.1 star was found to be the only object consistent with the X-ray position. VLT FORS spectra revealed a blue continuum with no intrinsic…

XMM-Newton archival observations of the Be/X-ray binary candidate RX J0103.6-7201 revealed pulsations with a period of ~1323 s. This makes RX J0103.6-7201 the X-ray pulsar with the longest period known in the Small Magellanic Cloud (SMC).…

The young, fast-spinning, X-ray pulsar J0537-6910 displays an extreme glitch activity, with large spin-ups interrupting its decelerating rotation every ~100 days. We present nearly 13 years of timing data from this pulsar, obtained with the…

The high mass X-ray binary (HMXB) V0332+53 became active at the end of 2004 and the outburst was observed at hard X-rays by RXTE and INTEGRAL. Based on these hard X-ray observations, the orbital parameters are measured through fitting the…

We report $I$-band photometric observations of the radio-detected M9.5 dwarf BRI 0021-0214, obtained with the Galway Ultra Fast Imager (GUFI) on the 1.8m Vatican Advanced Technology Telescope VATT at Mt. Graham International Observatory,…

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…

We present the results of precision gamma-ray timing measurements of the binary millisecond pulsar PSR J2339$-$0533, an irradiating system of "redback" type, using data from the Fermi Large Area Telescope. We describe an optimized analysis…

Long-term ("superorbital") periods or modulations have been detected in a wide variety of both low and high-mass X-ray binaries at X-ray and optical wavelengths. A variety of mechanisms have been proposed to account for the variability…

A probable binary period has been detected in the optical counterpart to the X-ray source CXOU J005455.6-724510 = RX J0054.9-7245 = AXJ0054.8-7244 = SXP504 in the Small Magellanic Cloud. This source was detected by Chandra on 04 Jul 2002…

Using the Rossi X-ray Timing Explorer and the Nordic Optical Telescope we have obtained the highest ever quality X-ray/white-light high-speed photometry of XB 1916-053. We refine the X-ray period (P_X) to 3000.6+/-0.2s via a restricted…

The persistent Be/X-ray binary RX J0440.9+4431 flared in 2010 and 2011 and has been followed by various X-ray facilities Swift, RXTE, XMM-Newton, and INTEGRAL. We studied the source timing and spectral properties as a function of its X-ray…

We report on the analysis of Rossi X-ray Timing Explorer (RXTE) Proportional Counter Array (PCA) monitoring observations of the $\gamma$-ray binary system LS I +61 303, covering 35 full cycles of its orbital motion. This constitutes the…

Magnetic cataclysmic variables are close binaries which consist of a compact object - a white dwarf - and a red dwarf filling its Roche Lobe. Such systems are physical laboratories which enable study of the influence of magnetic fields on…

We present a study of the recently discovered intermediate polar 1RXS J070407+262501, distinctive for its large-amplitude pulsed signal at P = 480 s. Radial velocities indicate an orbital period of 0.1821(2) d, and the light curves suggest…

Because of the previously observed stability of the 171-day period, the superorbital modulation of the low-mass X-ray binary 4U 1820-30 was considered a consequence of a third star orbiting around the binary. This study aims to further…

RX J0123.4-7321 is a well-established Be star X-ray binary system (BeXRB) in the Small Magellanic Cloud (SMC). Like many such systems the variable X-ray emission is driven by the underlying behaviour of the mass donor Be star. Previous work…

The recently discovered J0651+2844 is a detached, eclipsing white dwarf binary with an orbital period of 765 s. We investigate the prospects for the detection of gravitational radiation from this system and estimate the effect of the tidal…

We explore the long-term evolution of the spin period of the High Mass X-ray Binary (HMXB) pulsar Vela X-1 over a period of 46 yr. Our analysis indicates nearly periodic variations in the spin period of the pulsar on time-scales of about…

We report on NuSTAR, XMM-Newton and Swift observations of the gamma-ray binary 1FGL J1018.6-5856. We measure the orbital period to be 16.544+/-0.008 days using Swift data spanning 1900 days. The orbital period is different from the 2011…