Related papers: A Spectroscopic and Interferometric Study of W Ser…

Information extracted from the GAIA Data Release 3 is used to examine the stellar contents within projected separations of 10 parsecs from eight close binary systems that are either classical W Serpentis systems or related objects. The goal…

The unusual light curve of the massive eclipsing binary W Ser was recently observed with high S/N and fast cadence by the NASA TESS mission. The TESS light curve records two eclipses and relatively fast variations outside of the eclipses.…

Spectra that cover 0.63 - 0.69um with a spectral resolution ~ 17000 are presented of the W Serpentis system V367 Cygni. Absorption lines of FeII and SiII that form in a circumsystem shell are prominent features, and the depths of these are…

High resolution spectroscopic observations of AW UMa, obtained on three consecutive nights with the median time resolution of 2.1 minutes, have been analyzed using the Broadening Functions method in the spectral window Doppler images of the…

We derive precise system parameters for the pre-cataclysmic binary, NN Ser. From light curve fitting we find an orbital inclination of i = 89.6 +/- 0.2 deg. From the HeII absorption line we find K_{WD}= 62.3 +/- 1.9 km/s. The…

The massive interacting binary RY Scuti is an important representative of an active mass-transferring system that is changing before our eyes and which may be an example of the formation of a Wolf-Rayet star through tidal stripping.…

Symbiotic stars serve as exceptional laboratories for investigating mass transfer processes in binary systems. However, the dominant mechanism of mass transfer from the red giant donor to the compact accretor - typically a white dwarf or,…

Brown dwarfs and giant planets orbiting close to a host star are subjected to significant irradiation that can modify the properties of their atmospheres. In order to test the atmospheric models that are used to describe these systems, it…

We study the outflow activity, photometric variability and morphology of three very young stellar objects in the Serpens NW star forming region: OO Serpentis, EC 37 (V370 Ser) and EC 53 (V371 Ser). High spatial resolution Keck/NIRC2 laser…

The origin of the bright and hard X-ray emission flux among the gamma Cas subgroup of B-emission line (Be) stars may be caused by gas accretion onto an orbiting white dwarf (WD) companion. Such Be+WD binaries are the predicted outcome of a…

The B-W method is used to determine the distance of Cepheids and consists in combining the angular size variations of the star, as derived from infrared surface-brightness relations or interferometry, with its linear size variation, as…

The microquasar SS 433 is an interacting massive binary consisting of an evolved mass donor and a compact companion that ejects relativistic jets. The mass donor was previously identified through spectroscopic observations of absorption…

We present results from a short series of blue, moderate resolution spectra of the microquasar binary, SS 433. The observations were made at a time optimized to find the spectrum of the donor star, i.e., when the donor was in the foreground…

The Young Stellar Object (YSO) W33A is one of the best known examples of a massive star still in the process of forming. Here we present Gemini North ALTAIR/NIFS laser-guide star adaptive-optics assisted K-band integral-field spectroscopy…

The rapidly rotating Be star phi Persei was spun up by mass and angular momentum transfer from a now stripped-down, hot subdwarf companion. Here we present the first high angular resolution images of phi Persei made possible by new…

Results of spectroscopy of unusual symbiotic star MWC560 are presented. The data have been obtained from autumn 1990 to spring 1993. The high velocity absorption line profiles demonstrate their origin in a jet, directed closely to the line…

We present new optical and infrared (IR) observations of Cir X-1 taken near apastron. Both sets of spectra show asymmetric emission lines. Archival optical observations show that an asymmetric H-alpha emission line has been in evidence for…

V1022 Cas has been known as a spectroscopic binary for a century. It was found to be eclipsing based on photometry from the Hipparcos satellite, and an astrometric orbit was recently obtained from near-infrared interferometry. We present…

Using our new photometric and spectroscopic observations as well as all available published data, we present a new interpretation of the properties of the peculiar emission-line binary UX Mon. We conclude that this binary is in a rare phase…

Context. Determining the mass transfer in a close binary system is of prime importance for understanding its evolution. SS Leporis, a symbiotic star showing the Algol paradox and presenting clear evidence of ongoing mass transfer, in which…