BG Gem is an eclipsing binary with a 91.6-day orbital period. The more massive primary component does not seem to show absorption lines in the spectrum, while the less massive secondary is thought to be a K-type star, possibly a supergiant. These res
ults were obtained with optical low-resolution spectroscopy and photometry. The primary was suggested to be a black hole, although with a low confidence. We present a high-resolution optical spectrum of the system along with new BVR-photometry. Analysis of the spectrum shows that the K-type star rotates rapidly at v sin i = 18 km/s compared to most evolved stars of this temperature range. We also discuss constraints on the secondarys luminosity using spectroscopic criteria and on the entire system parameters using both the spectrum and photometry.
FF Cam is a variable star near the North celestial pole with hydrogen lines in emission. Its optical variability of ~0.3 mag was discovered by HIPPARCOS. The spectral type assigned to the star in SIMBAD is B9, but its position coincides with a ROSAT
X-ray source. This suggests the presence of a high-temperature region in the system that could originate at or near a companion object. We undertook a spectroscopic monitoring of FF Cam since the beginning of 2012 and found an extremely variable H-alpha line profile as well as periodically variable radial velocities of numerous absorption lines. The main conclusion from our study is that FF Cam is a binary system with an orbital period of 7.785 days, a B-type primary and a K-type secondary component. We discuss the spectral features, their variations, and the nature of FF Cam.
We describe the results of the world-wide observing campaign of the highly eccentric Be binary system delta Scorpii 2011 periastron passage which involved professional and amateur astronomers. Our spectroscopic observations provided a precise measure
ment of the system orbital period at 10.8092+/- 0.0005 years. Fitting of the He II 4686A line radial velocity curve determined the periastron passage time on 2011 July 3, UT 9:20 with a 0.9--day uncertainty. Both these results are in a very good agreement with recent findings from interferometry. We also derived new evolutionary masses of the binary components (13 and 8.2 Msun) and a new distance of 136 pc from the Sun, consistent with the HIPPARCOS parallax. The radial velocity and profile variations observed in the H_alpha line near the 2011 periastron reflected the interaction of the secondary component and the circumstellar disk around the primary component. Using these data, we estimated a disk radius of 150 Rsun. Our analysis of the radial velocity variations measured during the periastron passage time in 2000 and 2011 along with those measured during the 20th century, the high eccentricity of the system, and the presence of a bow shock-like structure around it suggest that delta Sco might be a runaway triple system. The third component should be external to the known binary and move on an elliptical orbit that is tilted by at least 40 degree with respect to the binary orbital plane for such a system to be stable and responsible for the observed long-term radial velocity variations.
Discovered over 30 years ago, the B[e] phenomenon has not yet revealed all its puzzles. New objects that exhibit it are being discovered in the Milky Way, and properties of known objects are being constrained. We review recent findings about objects
of this class and their subgroups as well as discuss new results from studies of the objects with yet unknown nature. In the Magellanic Clouds, the population of such objects has been restricted to supergiants. We present new candidates with apparently lower luminosities found in the LMC.
FS CMa type stars are a group of Galactic objects with the B[e] phenomenon. They exhibit strong emission-line spectra and infrared excesses, which are most likely due to recently formed circumstellar dust. The group content and identification criteri
a were described in the first two papers of the series. In this paper we report our spectroscopic and photometric observations of the optical counterpart of IRAS 00470+6429 obtained in 2003--2008. The optical spectrum is dominated by emission lines, most of which have P Cyg type profiles. We detected significant brightness variations, which may include a regular component, and variable spectral line profiles in both shape and position. The presence of a weak Li {sc I} 6708 AA line in the spectrum suggests that the object is most likely a binary system with a B2--B3 spectral type primary companion of a luminosity $log$ L/L$odot$ = 3.9$pm$0.3 and a late-type secondary companion. We estimate a distance toward the object to be 2.0$pm$0.3 kpc from the Sun.
