scholarly journals UBV Photometry of the Massive Eclipsing Binary TT Aur

2001 ◽  
Vol 18 (2) ◽  
pp. 151-157 ◽  
Author(s):  
S. Özdemir ◽  
H. Ak ◽  
M. Tanriver ◽  
H. Gülseçen ◽  
S. Gülseçen ◽  
...  
Keyword(s):  
Binary System ◽  
Primary Component ◽  
Light Curves ◽  
National Observatory ◽  
Simultaneous Solution ◽  
Primary Minimum ◽  
Circumstellar Material ◽  
System Parameters ◽  
Ubv Photometry ◽  
Excess Absorption

AbstractUBV observations of the massive binary system TT Aur were carried out mainly at theTurkish National Observatory (TUG). These observations, together with IUE spectra and times of eclipse minima collected from the literature, were used to study the system parameters.Simultaneous solution of the light curves by the Wilson-Devinney code allows a semi-detached configuration with a slightly larger Roche-lobe filling secondary. This picture is supported by other evidence. The shoulders of the primary minimum suggest some excess absorption, in keeping with circumstellar material in the form of a disk-like structure around the primary component. The deeper primary minimum in the U filter may indicate a hotter region on the secondary-facing hemisphere of the primary.The period variation of the system can also be related to the possible existence of a third component in a circular orbit around the system.An alternative detached representation is also considered using optimal curve-fitting techniques. We appeal for further observations to help resolve some outstanding issues in this interesting massive binary.

scholarly journals δ Sct-Type Pulsators in Eclipsing Binary Systems: the Case of RZ Cas

2002 ◽  
Vol 185 ◽  
pp. 102-103
Author(s):  
E. Rodríguez ◽  
V. Costa ◽  
M.J. López-González ◽  
J.M. García ◽  
S.L. Kim ◽  
...  
Keyword(s):  
Binary System ◽  
Binary Systems ◽  
Hot Spot ◽  
Primary Component ◽  
Roche Lobe ◽  
Light Curves ◽  
Eclipsing Binary ◽  
Preliminary Results ◽  
The Impact

AbstractRZ Cas is an Algol-type eclipsing binary system where the primary component was recently discovered as a δ Set pulsator. A three-continent multisite photometric campaign was carried out during 1999. Preliminary results are reported here indicating a semi-detached system where the secondary fills its Roche lobe. The light curves also suggest a hot spot on the surface of the primary component as a consequence of the impact of the mass stream from the secondary. The pulsational behaviour can be well described with only one frequency.

Symbiotic Nova PU Vul - 33 Years of Observations

2012 ◽  
Vol 21 (1-2) ◽  
Author(s):  
S. Shugarov ◽  
D. Chochol ◽  
E. Kolotilov
Keyword(s):  
Binary System ◽  
Light Curves ◽  
Secondary Minimum ◽  
Pulsation Period ◽  
Primary Minimum ◽  
Cool Component ◽  
Period Analysis ◽  
Binary Orbit ◽  
Orbit Period

AbstractWe present UBVRI light curves of the symbiotic nova PU Vul after its outburst in 1978. Three observed eclipses of the hot component by the cool one were used to determine the ephemeris of the binary system as JD (Min I) = 2444550(15) + 4897(10) × E days. the 194-day shift of the secondary minimum from its expected positions in 2001 suggests the eccentricity of the binary orbit. Period analysis of the VRI photometry improved the pulsation period of the cool AGB variable in the system to P = 217.7 days. Pulsation of the cool component is detected only in the phases around the primary minimum, when the visible hemisphere of the AGB star is not influenced by the interaction with the hot component.

scholarly journals Dust Shell around V718 Scorpii

1989 ◽  
Vol 107 ◽  
pp. 356-356
Author(s):  
M. Parthasarathy
Keyword(s):  
Binary System ◽  
Temperature Gradient ◽  
Point Source ◽  
Far Infrared ◽  
Primary Component ◽  
Dust Shell ◽  
Primary Minimum ◽  
Infrared Excess ◽  
Dust Temperature ◽  
Lower Temperature

V718 Sco (HD 145718 = SAO 184232) is an eclipsing-binary system with an orbital period of about 200d, depth of primary minimum about lṃ4 and a primary component of spectral type A2 (Wood et al., 1980). Neither period nor eclipse depth are well determined and the system has not been observed photoelectrically. The IRAS point-source catalogue (Beichman et al., 1985) contains an object having a far-infrared excess at a position closely agreeing with that given for V718 Scorpii in the S.A.0. catalogue. The fluxes (in Janskys) at 12 µm, 25 µm, 60 µm and 100 µm are 5.73, 5.92, 4.91, 3.37 respectively and this distribution suggests that V718 Sco is surrounded by a dust envelope in which there is a temperature gradient. From the ratios of the fluxes, a dust temperature of about 140 K is found; the fluxes at 60 μm and 100 μm would suggest a lower temperature.

A survey of extended matter around chromospherically active binary systems

2020 ◽  
Vol 37 ◽  
Author(s):  
Osman Karakuş ◽  
Fehmi Ekmekçi
Keyword(s):  
Binary System ◽  
Observational Data ◽  
Binary Systems ◽  
National Observatory ◽  
Active Components ◽  
Primary Minimum ◽  
Evolutionary Processes ◽  
Stellar Activity ◽  
Binary Component ◽  
Colour Excess

Abstract We present an analysis of colour excess (CE) observations for 13 chromospherically active binary systems, together with 27 inactive reference stars of similar spectral types and luminosity classes of the components of these 13 binaries. We used the observations which were made by Johnson-Cousins ${BVR}_{c}\mathrm{I}_{c}$ , 2MASS, and WISE photometric systems. Our new photometric ${BVR}_{c}\mathrm{I}_{c}$ observations were obtained by means of 1 m telescope at TÜBİTAK National Observatory and 40 cm telescope at Ankara University Kreiken Observatory. To check the existence of extended matter around an active binary component(s) of these 13 binary systems, we examined the CE values at around primary/secondary minima and outside eclipses. The comparison of these CEs, obtained relative to those of reference stars of the same ${(B-V)_\circ}$ colours, especially during primary minima with those of secondary minima and outside eclipses, showed that these systems have greater excess radiation in primary minima than in both secondary minima and outside eclipses. We observed that the colour excesses, in general, most likely arise from the extended matter around the cooler component of a binary system. The comparison of CE values also showed that the extended matter of some of these systems was most likely covered or affected both of their components. Since no observational data were obtained during primary minimum of RW UMa, by excluding this binary system, an examination of the locations of cool and active components of the remaining 12 systems of this study on Hertzsprung-Russell diagram, together with corresponding evolutionary tracks, showed that most of the active binary systems have an extended matter not only caused from stellar activity but also more likely caused from evolutionary processes.

scholarly journals BVRI Light Curves and Period Analysis of the Beta Lyrae System XX Leonis

2006 ◽  
Vol 2 (S240) ◽  
pp. 551-554
Author(s):  
P. Zasche ◽  
P. Svoboda ◽  
M. Wolf
Keyword(s):  
Binary System ◽  
Primary Component ◽  
Light Curves ◽  
Minimum Mass ◽  
Mass Ratio ◽  
Third Body ◽  
Photometric Analysis ◽  
Period Analysis ◽  
The Third ◽  
Ccd Detector

AbstractThe contact eclipsing binary system XX Leonis (p = 0.97 days, Sp A9) has been analysed using the PHOEBE programme, based on the Wilson–Devinney code. The BVRI light curves were obtained during spring 2006 using the 20-cm telescope and ST-7 CCD detector. The effective temperature of the primary component determined from the photometric analysis is T = (7342 ± 14) K, the inclination of the orbit is i = (84.83 ± 0.29)° and the photometric mass ratio q = (0.40 ± 0.01). The third-body hypothesis was also suggested; based on a period analysis using 57 minimum times this gave a period for the third body of p3 = (59.66 ± 0.05) yr, an amplitude of A = (0.036 ± 0.028) day and zero eccentricity, which yields as a minimum mass M3,min = (0.91 ± 0.01) M⊙.

The Eclipsing Binary WX Eridani

1979 ◽  
Vol 46 ◽  
pp. 385
Author(s):  
M.B.K. Sarma ◽  
K.D. Abhankar
Keyword(s):  
Light Curve ◽  
Spectral Type ◽  
Orbital Period ◽  
Primary Component ◽  
Light Curves ◽  
Absorption Feature ◽  
Primary Star ◽  
Eclipsing Binary ◽  
The Times ◽  
Phase Angles

AbstractThe Algol-type eclipsing binary WX Eridani was observed on 21 nights on the 48-inch telescope of the Japal-Rangapur Observatory during 1973-75 in B and V colours. An improved period of P = 0.82327038 days was obtained from the analysis of the times of five primary minima. An absorption feature between phase angles 50-80, 100-130, 230-260 and 280-310 was present in the light curves. The analysis of the light curves indicated the eclipses to be grazing with primary to be transit and secondary, an occultation. Elements derived from the solution of the light curve using Russel-Merrill method are given. From comparison of the fractional radii with Roche lobes, it is concluded that none of the components have filled their respective lobes but the primary star seems to be evolving. The spectral type of the primary component was estimated to be F3 and is found to be pulsating with two periods equal to one-fifth and one-sixth of the orbital period.

scholarly journals New Data on the Eclipsing Binary V1848 Ori and Improved Orbital and Light Curve Solutions

2020 ◽  
Vol 29 (1) ◽  
pp. 72-80 ◽  
Author(s):  
Fatemeh Davoudi ◽  
Atila Poro ◽  
Fahri Alicavus ◽  
Afshin Halavati ◽  
Saeed Doostmohammadi ◽  
...  
Keyword(s):  
Binary System ◽  
Light Curve ◽  
Mass Function ◽  
Light Curves ◽  
Complete Analysis ◽  
Physical Parameters ◽  
Mass Ratio ◽  
Third Body ◽  
Eclipsing Binary

AbstractNew observations of the eclipsing binary system V1848 Ori were carried out using the V filter resulting in a determination of new times of minima and new ephemeris were obtained. We presented the first complete analysis of the system’s orbital period behavior and analysis of O-C diagram done by the GA and MCMC approaches in OCFit code. The O-C diagram demonstrates a sinusoidal trend in the data; this trend suggests a cyclic change caused by the LITE effect with a period of 10.57 years and an amplitude of 7.182 minutes. It appears that there is a third body with mass function of f (m3) = 0.0058 M⊙ in this binary system. The light curves were analyzed using the Wilson-Devinney code to determine some geometrical and physical parameters of the system. These results show that V1848 Ori is a contact W UMa binary system with the mass ratio of q = 0.76 and a weak fillout factor of 5.8%. The O’Connell effect was not seen in the light curve and there is no need to add spot.

The Massive Binary System RY Sct – New Solution of the Light Curves

Astrophysics ◽  
2020 ◽  
Vol 63 (2) ◽  
pp. 243-251
Author(s):  
N. Kochiashvili ◽  
I. Kochiashvili ◽  
R. Natsvlishvili ◽  
S. Beradze ◽  
M. Vardosanidze
Keyword(s):  
Binary System ◽  
Light Curves

scholarly journals Doppler Tomography in 2D and 3D of the X-ray Binary Cyg X-1 for June 2007

2011 ◽  
Vol 7 (S282) ◽  
pp. 201-202 ◽  
Author(s):  
O. I. Sharova ◽  
M. I. Agafonov ◽  
E. A. Karitskaya ◽  
N. G. Bochkarev ◽  
S. V. Zharikov ◽  
...  
Keyword(s):  
Binary System ◽  
Spectral Data ◽  
Inclination Angle ◽  
Tomographic Reconstruction ◽  
Orbital Plane ◽  
National Observatory ◽  
Doppler Tomography ◽  
X Ray ◽  
2D And 3D ◽  
First Time

AbstractThe 2D and 3D Doppler tomograms of X-ray binary system Cyg X-1 (V1357 Cyg) were reconstructed from spectral data for the line HeII 4686Å obtained with 2-m telescope of the Peak Terskol Observatory (Russia) and 2.1-m telescope of the Mexican National Observatory in June, 2007. Information about gas motions outside the orbital plane, using all of the three velocity components Vx, Vy, Vz, was obtained for the first time. The tomographic reconstruction was carried out for the system inclination angle of 45°. The equal resolution (50 × 50 × 50 km/s) is realized in this case, in the orbital plane (Vx, Vy) and also in the perpendicular direction Vz. The checkout tomograms were realized also for the inclination angle of 40° because of the angle uncertainty. Two versions of the result showed no qualitative discrepancy. Details of the structures revealed by the 3D Doppler tomogram were analyzed.

scholarly journals The circumstellar environment of the B[e] star GG Car: an interferometric modeling

2014 ◽  
Vol 9 (S307) ◽  
pp. 291-292
Author(s):  
A. Domiciano de Souza ◽  
M. Borges Fernandes ◽  
A. C. Carciofi ◽  
O. Chesneau
Keyword(s):  
Binary System ◽  
Primary Component ◽  
Compact Ring ◽  
Hot Stars ◽  
Self Consistent ◽  
Grain Formation ◽  
Formation And Evolution ◽  
Circumstellar Environments ◽  
Consistent Treatment ◽  
Circumstellar Environment

AbstractThe research of stars with the B[e] phenomenon is still in its infancy, with several unanswered questions. Physically realistic models that treat the formation and evolution of their complex circumstellar environments are rare. The code HDUST (developed by A. C. Carciofi and J. Bjorkman) is one of the few existing codes that provides a self-consistent treatment of the radiative transfer in a gaseous and dusty circumstellar environment seen around B[e] supergiant stars. In this work we used the HDUST code to study the circumstellar medium of the binary system GG Car, where the primary component is probably an evolved B[e] supergiant. This system also presents a disk (probably circumbinary), which is responsible for the molecular and dusty signatures seen in GG Car spectra. We obtained VLTI/MIDI data on GG~Car at eight baselines, which allowed to spatially resolve the gaseous and dusty circumstellar environment. From the interferometric visibilities and SED modeling with HDUST, we confirm the presence of a compact ring, where the hot dust lies. We also show that large grains can reproduce the lack of structure in the SED and visibilities across the silicate band. We conclude the dust condensation site is much closer to the star than previously thought. This result provides stringent constraints on future theories of grain formation and growth around hot stars.

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