Related papers: Sub-Subgiants in the Old Open Cluster M67?

BD+6073 is the optical counterpart of the X-ray source IGR J00370+6122, a probable accretion-powered X-ray pulsar. The X-ray light curve of this binary system shows clear periodicity at 15.7 d, which has been interpreted as repeated…

We present the first detailed analysis of the detached eclipsing binary V15 in the super-metal rich open cluster NGC 6253. We obtain the following absolute parameters: M_p=1.303+-0.006 Msun, R_p=1.71+-0.03 Rsun, L_p=2.98+-0.10 Lsun for the…

This paper reports the discovery of an Algol system KIC 10736223 that just past the rapid mass transfer stage. From the light curve and radial-velocity modelling we find KIC 10736223 to be a detached Algol system with the less-massive…

We present Chandra X-ray Observatory ACIS-S3 X-ray imaging observations and VLT/FORS2 and Hubble Space Telescope optical observations of two low-density Galactic globular clusters; NGC 6366 and M55. We detect 16 X-ray sources with 0.5-6.0…

The percentage of massive main sequence OB stars in binary systems is thought to be as high as 100%. However, very few Galactic binary red supergiants (RSGs) have been identified, despite the fact that these stars are the evolved…

Thirteen spectroscopic orbits of late-type stars are determined from the high-resolution spectra taken with the CHIRON echelle spectrometer at the 1.5-m CTIO telescope. Most (HIP 14194B, 40523A, 41171A, 51578A, 57572B, 59426A, 62852B,…

Multiple radial velocity observations have been obtained for a large sample of local field subdwarf B (sdB) stars over a period of two years. SdB stars appear to fall into three distinct groups based on their kinematic and spectroscopic…

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…

Spectroscopic multiplicity surveys of O stars in young clusters and OB associations have revealed that a large portion ($\sim$ 70%) of these massive stars (M$_{i}$ $\gt$ 15 $M_{\odot}$) belong to close and short-period binaries (physical…

We present a detailed study of the cluster pair SL 353 & SL 349. This candidate binary cluster is located at the northwestern rim of the LMC bar. Based on photometric data we find that both clusters are coeval with an age of 550 +/- 100…

The current theory predicts that hot subdwarf binaries are produced from evolved low-mass binaries that have undergone mass transfer and drastic mass loss during either a common envelope phase or a stable Roche lobe overflow while on the…

We report on a three year spectroscopic monitoring program of the H-alpha emission in the massive X-ray binary LS I +65 010 = 2S 0114+650, which consists of a B-supergiant and a slowly rotating X-ray pulsar. We present revised orbital…

We present MMT spectroscopic observations of two massive galaxy cluster candidates at redshift $z\sim0.07$ that show extended and diffuse X-ray emission in the ROSAT All Sky Survey (RASS) images. The targets were selected from a previous…

NSVS 14256825 is the second sdOB + dM eclipsing binary systems with an orbital period of 2.65 hours. The special binary was reported to contain circumbinary planets or brown dwarfs by using the timing method. However, different results were…

We present Hubble Space Telescope far-ultraviolet (FUV) spectra of a blue-lurker$-$white-dwarf (BL-WD) binary system in the 4 Gyr open cluster M67. We fit the FUV spectrum of the WD, determining it is a C/O WD with a mass of…

We report the results of our radial-velocity monitoring of spectroscopic binary systems in a sample of X-ray sources from the ROSAT All Sky Survey south of the Taurus-Auriga star-forming region. The original sample of approximately 120…

We employed the Fast Folding Algorithm (FFA) on L-Band Globular Cluster (GC) observations taken with Five-hundred-meter Aperture Spherical radio Telescope (FAST) to search for new pulsars, especially those with a long rotational period. We…

Hot subdwarf stars with F-K main sequence binary companions have been known for decades, but the first orbital periods for such systems were published just recently. Current observations suggest that most have long periods, on the order of…

We present 35 new spectroscopic-binary orbits from our extended radial-velocity (RV) survey of the old ($6.4 \pm 0.2$ Gyr) open cluster NGC 188. Using data from the WIYN Open Cluster Study (WOCS) and APOGEE-2, this work nearly doubles the…

Models of stellar structure and evolution can be constrained using accurate measurements of the parameters of eclipsing binary members of open clusters. Multiple binary stars provide the means to tighten the constraints and, in turn, to…