Related papers: R144 revealed as a double-lined spectroscopic bina…
We present radial velocity observations of four binary white dwarf candidates identified through their over-luminosity. We identify two new double-lined spectroscopic binary systems, WD 0311-649 and WD 1606+422, and constrain their orbital…
The X-ray source 4U1820-30 in the globular cluster NGC 6624 is known as the most compact binary among the identified X-ray binaries. Having an orbital period of 685.0 s, the source consists of a neutron star primary and likely 0.06--0.08…
The radio millisecond pulsar PSR B1620-26 is part of an extraordinary triple star system in the globular cluster M4. The inner companion to the neutron star is thought to be a white dwarf of mass m1 ~0.3 Msun in an orbit of period ~0.5…
We have found that the white dwarf PG 1101+364 is a double-lined white dwarf/white dwarf binary with an orbital period of 3.47 hours. PG 1101+364 is the shortest period detached double-degenerate yet found and gravitational radiation will…
Spin properties and spectral variations of high mass X-ray binary 4U 2206+54 are studied with long-term hard X-ray monitoring observations by INTEGRAL. A long-period X-ray pulsar of P_spin\sim 5558 s has been identified in 4U 2206+54. The…
We present the orbital solutions for four OB spectroscopic binaries, MT145, GSC 03161-00815, 2MASS J20294666+4105083, and Schulte 73, and the partial orbital solution to the B spectroscopic binary, MT372, as part of an ongoing study to…
PSR J1744-3922 is a binary pulsar exhibiting highly variable pulsed radio emission. We report on a statistical multi-frequency study of the pulsed radio flux variability which suggests that this phenomenon is extrinsic to the pulsar and…
LoTr 5 is a planetary nebula with an unusual long-period binary central star. As far as we know, the pair consists of a rapidly rotating G-type star and a hot star, which is responsible for the ionization of the nebula. The rotation period…
The importance of long-period binaries on the formation and evolution of planetary nebulae is still rather poorly understood, in part due to the lack of central star systems known to comprise such long-period binaries. Here, we report on…
The remarkable hot R Coronae Borealis star DY Cen is revealed to be the first and only binary system to be found among the R Coronae Borealis (RCB) stars and their likely relatives, including the Extreme Helium stars and the…
Context. Most massive stars are in binary or multiple systems. Several massive stars have been detected as doublelined spectroscopic binaries and among these, the OWN Survey has detected a non-negligible number whose components show very…
Radial velocities analysis based on high-resolution spectra, obtained in the H$\alpha$ region and low resolution spectra obtained in the region 4420-4960\AA together with radial velocities, taken from other published sources allow us to…
CXOU J121538.2+361921 is the brightest X-ray source in the galaxy NGC 4214, with an X-ray luminosity of up to 0.7 x 10^39 erg/s. The observed periodicity of 3.62 hr is interpreted as the orbital period of the system. It has been suggested…
We report on the spectroscopic monitoring of GCIRS16SW, an Ofpe/WN9 star and LBV candidate in the central parsec of the Galaxy. SINFONI observations show strong daily spectroscopic changes in the K band. Radial velocities are derived from…
The star NGC 3603-A1 has long been known to be a very massive binary, consisting of a pair of O2-3If*/WN5-6 stars, which show Wolf-Rayet-like emission due to their luminosities being near the Eddington limit. The system has been poorly…
We examine the spectroscopic binary population for two massive nearby regions of clustered star formation, the Orion Nebula Cluster and NGC 2264, supplementing the data presented by Tobin et al. (2009, 2015) with more recent observations…
We report the first time-resolved photometric and spectroscopic optical observations of the X-ray source RX J2133.7+5107, identified in the ROSAT survey. A clear persistent optical light pulsation is discovered with fast photometry at a…
The A-type star HR 6412 = V2368 Oph was used by several investigators as a photometric comparison star for the known eclipsing binary U Oph but was found to be variable by three independent groups, including us. By analysing series of new…
Wide binaries are tracers of the gravity field of the Galaxy, but their study requires some caution. A large list of common proper motion stars selected from the AGK3 were monitored with the CORAVEL spectrovelocimeter, in order to prepare a…
In the course of our search for double degenerate (DD) binaries as potential progenitors of type Ia supernovae with the UVES spectrograph at the ESO VLT (ESO SN Ia Progenitor surveY - SPY) we discovered that the white dwarf HE 1414-0848 is…