Orbital parameters of the high‐mass X‐ray binary 4U 2206+54

We present new radial velocities of the high‐mass X‐ray binary star 4U 2206+54 based on optical spectra obtained with the Coudé spectrograph at the 2 m RCC telescope of the Rozhen National Astronomical Observatory, Bulgaria in the period November 2011–July 2013. The radial velocity curve of the He I δ6678 Å line is modeled with an orbital period P_orb = 9.568 d and an eccentricity of e = 0.3. These new measurements of the radial velocity resolve the disagreements of the orbital period discussions. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Photometric analysis of the eclipsing binary 2MASS 19090585+4911585

We report on observations of the eclipsing binary 2MASS 19090585+4911585 with the 25 cm auxiliary telescope of the University Observatory Jena. We show that a nearby brighter star (2MASS 19090783+4912085) was previously misclassified as the eclipsing binary and find 2MASS 19090585+4911585 to be the true source of variation. We present photometric analysis of VRI light curves. The system is an overcontact binary of W UMa type with an orbital period of (0.288374 ± 0.000010) d (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

A New Magnetically Active Binary System Discovered in Yunnan-Hong Kong Wide Field Survey

We present a newly discovered magnetically active binary system detected by Yunnan-Hong Kong wide field survey, with an orbital period of 0.60286 days. Two color photometry for the system was performed using the 1 m Cassegrain telescope of Yunnan Observatories with its CCD (Charge-Coupled Device) camera. In the observed light curves, there are clearly different light maxima existed in the out-of-eclipse regions. We made spectroscopic observations for the binary system using the 2.4 m telescope and YFOSC (Yunnan Faint Object Spectrograph and Camera) of Lijiang station of Yunnan Observatories, China. The radial velocity curve was derived for primary star of the binary system. The primary star exhibited strong chromospheric activity, which confirms that the distortion of the light curves results from the starspot activity on the primary star. Through analyzing the light curves and RV (Radial Velocity) curve mentioned above by means of the W-D (Wilson-Devinney) code, orbital parameters and starspot configuration of the binary system are obtained. Finally, we have discussed the properties of the binary system, and given the prospects on the future work.     

Optical identifications of five INTEGRAL hard X-ray sources in the Galactic plane

The results of optical identifications of five hard X-ray sources in the Galactic plane from the INTEGRAL all-sky survey are presented. The X-ray data on one source (IGR J20216+4359) are published for the first time. The optical observations were performed with the 1.5-m RTT-150 telescope (Turkish National Observatory, Antalya, Turkey) and the 6-m BTA telescope (Special Astrophysical Observatory, Nizhny Arkhyz, Russia). A blazar, three Seyfert galaxies, and a high-mass X-ray binary are among the identified sources.     

The orbit of the double-line spectroscopic binary system HR 7112

We present velocity observations, obtained with the E. W. Fick Observatory 0.6 m telescope, of the 7th magnitudeK1 star HR 7112. Our observations show that HR 7112 is a double-line spectroscopic binary system composed of almost equal mass stars with a period of 215.6 days. The orbit has an eccentricitye = 0.142 and the stars orbit each other with a mean semi-major axis distance of approximately 0.4sin(i) AU. The masses of the stars are consistent with the classification as giant stars. Tidal effects are known to circularise the orbits of giant stars and this process is apparently underway in this system.     

云南-香港宽视场巡天新发现的一个磁活动双星系统

云南-香港宽视场巡天新发现了一个磁活动双星系统,其轨道周期为0.60286 d.利用云南天文台1 m光学望远镜附加CCD (Charge-Coupled Device)相机,观测得到了这个双星系统的V、Rc双色光变曲线,结果表明该系统食外存在明显的测光畸变.借助云南天文台丽江2.4 m望远镜附加云南暗弱天体光谱成像仪(Yunnan Faint Object Spectrograph and Camera, YFOSC)对该双星系统的分光观测,测定了该双星系统主星的视向速度曲线并发现该系统的主星表面存在着强烈的色球活动,从而证明系统的光变曲线畸变源自主星的黑子活动.使用W-D (Wilson-Devinney)程序分析上述观测得到的光变曲线和视向速度曲线,得到了该双星系统的轨道参数以及黑子参数.最后,对该系统的特性进行了讨论并对未来的工作进行了展望.     

First Ground-Based Photometry and Light Curve Analysis of the Recently Discovered Contact Binary Hx Uma

Photoelectric UBV light curves of the recently discovered eclipsing binary HX UMa were obtained and studied to determine the preliminary physical parameters of the system for the first time. The observations were taken at the TüBİTAK¹ – Turkish National Observatory (TUG) on three nights in April 2003. A simultaneous analysis of the light and radial velocity curves yields a typical A-type contact binary with a high degree of overcontact. The influence of the close visual companion to the total light of the system was taken into account during the analysis. ¹TüBİTAK: The Scientific and Technical Research Council of Turkey.     

Orbital and physical parameters of the spectroscopic binary HD37737

We report the physical and orbital parameters of the visible component of the spectroscopic binary HD37737 (m _V = 8.03). The observations were performed with the 1.2-m telescope of the Kourovka Astronomical Observatory of the Ural Federal University in 2012 and the 6-m BTA telescope of the SAO RAS in 2007 and 2009. Radial velocities were measured separately from each spectral line of the list by the cross-correlation method with a synthetic spectrum. The latter was calculated using the grids of non-LTE model atmospheres with solar chemical compositions. A significant difference in the epochs of observations (2005–2012) allowed to refine the orbital period of the star (7 _· ^d 84705) and the orbital elements of the binary system. We obtained an estimate of the mass function f(m) = 0.23 ± 0.02M _⊙. The best agreement between the synthetic and observed spectra is achieved at T _eff = 30 000 K and log g = 3.50 according to the observations on both instruments. The obtained parameters correspond to a star of spectral type O9.5 III, with mass estimated at 26 ± 2M _⊙. The minimum mass estimate of the secondary component of the binary is 6.2 ± 0.5M _⊙. We have discovered a fact that the velocities, obtained from different spectral lines, differ, which is typical for giant stars. Engaging additional spectra, obtained in 2005 with the 2.1-m KPNO telescope, we investigated the effect of this fact on the estimate of the speed of the system’s center of mass. The difference in the velocities of various lines is approximately the same in the spectra, obtained at all the three instruments. The obtained ratios suggest that the deeper layers of the atmosphere of the star are moving with a greater velocity than the outer layers. Depending on the line, the estimate of the heliocentric velocity of the binary’s center of mass varies in the range from ?11 to 1 km/s.     

Pulsation and orbit of AU Pegasi

AU Pegasi is a pulsating star in a spectroscopic binary system with an orbital period of 53.26 days. Between 1960 and 1990 an extremely rapid period increase was observed in the value of the pulsation period, but in the last 15 years the observation show that the period set in 2.411 days. Fourier analysis of photometric data obtained during the ASAS project and those taken at the Piszkéstető Mountain Station of the Konkoly Observatory during 1994–2005 indicate that AU Pegasi is pulsating in two modes simultaneously, and the ratio of the frequencies of the two modes is 0.706, a value common for double‐mode classical Cepheids. A careful analysis of other photometric observations obtained during the era of the strong period increase also revealed existence of a second mode. This may suggest that this star is not a Type II Cepheid, despite its galactic position. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Infrared speckle interferometry of eleven binaries using a bispectral analysis

Infrared speckle-masking observations of eleven binary systems with the 6-m Special Astrophysical Observatory telescope are presented. A resolution of 43 mas in J (1.25 µm) and 76 mas in K (2.2 µm) has been achieved in reconstructed images. Accurate magnitude differences, separations, and position angles have been determined for all the resolved binaries. The pair HR 1071 with an abnormally low lithium abundance is considered in more detail.     

Parameters of the apparent relative orbit of the third body in the SZ Cam system

A complete set of parameters of the apparent relative orbit of the third body in the SZ Cam system is determined for the first time based on new speckle-interferometric and photometric observations of the eclipsing binary SZ Cam made with the 6-m telescope of the Special Astrophysical Observatory of the Russian Academy of Sciences and 0.5-m telescope of the Astronomical Observatory of Ural State University and published data. The mass of the third body and the distance to SZ Cam are estimated at M ₃ = 23.4M _⊙ and d = 1125 kpc, respectively. The binary nature of the third body is confirmed. It is suggested that SZ Cam is possibly not a member of the open star cluster NGC 1502 onto whose center it projects. A total of 16 new times of minima of SZ Cam are reported.     

Flickering in the Magnetic Cv Star Am Herculis

In this study, we present a photometric study of AM Her, a prototype of a class of magnetic CVs. Optical photometry of AM Her was obtained using the Russian–Turkish 1.5 m telescope at TüBİTAK National Observatory (TUG) in August 2003. The R band light curve of the system shows two maxima and two minima during one orbital cycle. In both observing nights the star showed flickering at a significant level. The measured flickering time scale is about 5 min.     

First results of the Central-East-South European Binary Star Study Group (CESEB)

Several eclipsing binary systems have been selected for combined spectral and photometric observations using the Bulgarian NAO 2 m telescope and several smaller telescopes located at various places in the CESE region. Preliminary results, based on a pilot study started in 2001, about radial velocity and light curve variations of the active W UMa system LS Del are presented here.     

Orbital solution for the MACHO*05:34:41.3–69:31:39 O3 If* +O6:V eclipsing binary system in the Large Magellanic Cloud

An orbital solution for the MACHO*05:34:41.3–69:31:39 eclipsing binary system is presented, based on the published light curve and spectral data obtained with the 2.15-m telescope at CASLEO. Based on these spectroscopic observations, the binary components of this system were classified as O3 If* and O6:V respectively. The radial velocity data along with the published light curve were analysed with the Wilson–Devinney code to derive the following masses and radii for the components of this system:             and     The solution shows that the system is in overcontact, as one would expect from the derived masses and the very short orbital period (∼1.4 d).     

Spectral observations of the eclipsing binary RY Sct

Spectral observations of the eclipsing binary RY Sct during 2005 and 2009 on the 2.6-m telescope at the Byurakan Observatory are reported. Although RY Sct requires further, more detailed study, the present limited observations reveal a number of important aspects of this star. The maxima of the equivalent widths are observed close to the primary minimum, while their minima are detected at the brightness maximum, where the spectral lines have very narrow profiles. Emission in the HeI λ6678? line was seen throughout the observation period, but transforms into weak absorption halfway between the secondary minimum and the maximum. The observed P-Cyg type changes in the profile of some lines indicates a variable outflow of mass from the star. Estimates of the average velocity based on the blue components of the absorption lines yield roughly 400 km/s. The main observational characteristics of RY Sct are closely related to its orbital period. In all likelihood, its complicated spectrum and features are at least partially caused by intense, variable outflows of matter.     

Orbital Parameters of the Binary Companion in o and Using Spectrum Disentangling

o And is one of the most frequently observed Be stars, both in photometry and spectroscopy. It is a multiple system of at least four stars (a Be star, a close binary of spectral types B7 and B8, and an A star). For over a century, numerous observers report a highly variable spectrum, photometric changes, and a substantial range of radial velocity. The star has changed back and forth between a shell-type and a normal B-type star. The last emission phase started in 1992 and ended in 2000. Analysis of the dynamical spectra at spectral lines Mg II 4481 Å and He I 6678 Å and radial velocity curves shows that the two binary components can be resolved. We decomposed the triple star spectra and computed orbital parameters of the binary companion using the KOREL code for spectrum disentangling.     

Spectral disentangling of the triple system DG Leo: orbits and chemical composition

DG Leo is a spectroscopic triple system composed of three stars of late-A spectral type, one of which was suggested to be a δ Scuti star. Seven nights of observations at high spectral and high time-resolution at the Observatoire de Haute-Provence with the ELODIE spectrograph were used to obtain the component spectra by applying a Fourier transform spectral disentangling technique. Comparing these with synthetic spectra, the stellar fundamental parameters (effective temperature, surface gravity, projected rotation velocity and chemical composition) are derived. The inner binary consists of two Am components, at least one of which is not yet rotating synchronously at the orbital period though the orbit is a circular one. The distant third component is confirmed to be a δ Scuti star with normal chemical composition.     

The Parkes Multibeam Pulsar Survey: PSR J1811−1736, a pulsar in a highly eccentric binary system

We are undertaking a high-frequency survey of the Galactic plane for radio pulsars, using the 13-element multibeam receiver on the 64-m Parkes radio telescope. We describe briefly the survey system and some of the initial results. PSR J1811−1736, one of the first pulsars discovered with this system, has a rotation period of 104 ms. Subsequent timing observations using the 76-m radio telescope at Jodrell Bank show that it is in an 18.8-d, highly eccentric binary orbit. We have measured the rate of advance of periastron which indicates a total system mass of 2.6±0.9 M_⊙, and the minimum companion mass is about 0.7 M_⊙. This, the high orbital eccentricity and the recycled nature of the pulsar suggest that this system is composed of two neutron stars, only the fourth or fifth such system known in the disc of the Galaxy.     

Spectroscopic binaries near the North Galactic Pole paper 6: BD 33° 2206

Photoelectric radial-velocity measurements have confirmed O. C. Wilson’s finding that BD 33° 2206, the secondary star in the wide visual binary ADS 8470, is a spectroscopic binary. It has an eccentric orbit with a period of 100 days. Its γ-velocity is close to the constant radial velocity of the visual primary, confirming the physical association of the stars.