Related papers: Orbital Parameters of the Microquasar LSI +61 303
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 present the results of an H-alpha monitoring campaign on the BeXRB and microquasar system LS I +61 303. We use radial velocity measurements of HeI lines in our spectra to re-evaluate the orbital elements and to better establish the time…
In this study, X-ray spectral and pulse timing analysis of the high mass X-ray binary (HMXB) pulsar 4U 1907+09, based on the observations with RXTE are presented. Spin rate measurements indicate a new spin-down episode with a rate close to…
With recent and archival Rossi X-Ray Timing Explorer (RXTE) X-ray measurements of the heavily obscured X-ray pulsar IGR J16393-4643, we carried out a pulse timing analysis to determine the orbital parameters. Assuming a circular orbit, we…
A new high-quality set of orbital parameters for the O-type spectroscopic binary HD93205 has been obtained combining echelle and coude CCD observations. The radial velocity orbits derived from the HeII 4686 A (primary component) and HeI…
We present high resolution echelle spectra taken during four observing runs from 1999 to 2001 of the recently X-ray/EUV selected chromospherically active binary BK Psc (2RE J0039+103). Our observations confirm the single-lined spectroscopic…
GX 301-2, a bright HMXB with an orbital period of 41.5 days, exhibits stable periodic orbital intensity modulations with a strong pre-periastron X-ray flare. Several models have been proposed to explain the accretion at different orbital…
We report NuSTAR observations of the millisecond pulsar - low mass X-ray binary (LMXB) transition system PSR J1023+0038 from June and October 2013, before and after the formation of an accretion disk around the neutron star. Between June…
LSI +61 303 is one of the few X-ray binaries with a Be star companion from which radio, X-rays and high-energy gamma-ray (GeV and TeV) emission have been observed. The nature of the high energy activity of the system is not yet fully…
We present X-ray and optical observations of a new transient X-ray source in M31 first detected 23-May-2004 at R.A.=00:43:09.940 +/- 0.65'', Dec.=41:23:32.49 +/- 0.66''. The X-ray lightcurve shows two peaks separated by several months,…
We present results on parallaxes, magnitudes and proper motions for 17 optically identified massive X-ray binaries (MXRB) which were observed during the Hipparcos astrometry mission. This sample includes the sources detected in the…
We report the results from our analysis of 8 years of the data for the gamma-ray binary LS I +61 303, obtained with the Large Area Telescope onboard the Fermi Gamma-Ray Space Telescope. We find a significant dip around the binary's…
The binary system, LSI+61 303, is unusual both because of the dramatic, periodic, radio outbursts, and because of its possible association with the 100 MeV gamma-ray source, 2CG135+01. We have performed simultaneous radio and Rossi X-ray…
In this Paper we report on optical spectroscopic observations of the low-mass X-ray binary 2S 0921-630 obtained with the Very Large Telescope. We found sinusoidal radial velocity variations of the companion star with a semi-amplitude of…
We observed stars with variable radial velocities to determine their spectroscopic orbits. Velocities of 132 targets taken over a time span reaching 30 years are presented. They were measured with the correlation radial velocity…
LSI +61 303 is an exotic binary system consisting of a ~10 Msun B star and a compact object which is probably a neutron star. The system is associated with the interesting radio source GT0236+610 that exhibits bright radio outbursts with a…
We monitored three transits of the giant gas planet around the nearby K dwarf HD 189733 with the ACS camera on the Hubble Space Telescope. The resulting very-high accuracy lightcurve (signal-to-noise ratio near 15000 on individual…
After the first detection of its binary nature, the spectroscopic monitoring of the non-thermal radio emitter Cyg OB2 #9 (P=2.4yrs) has continued, doubling the number of available spectra of the star. Since the discovery paper of 2008, a…
Typical radio pulsars are magnetized neutron stars that are born rapidly rotating and slow down as they age on time scales of 10 to 100 million years. However, millisecond radio pulsars spin very rapidly even though many are billions of…
We have detected a transient X-ray source in the M31 bulge through a continuing monitoring campaign with the Chandra ACIS-I camera. The source was detected at R.A.=00:42:33.428 +/- 0.11'', Dec.=+41:17:03.37 +/- 0.11'' in only a single…