Binary Systems Research Articles

Molecular dynamics simulations and FTIR Spectroscopy investigations on the hydration, transport, and dielectric properties of the NaF(aq) system at various concentrations

Sodium fluoride has many applications in various fields, such as dentistry, geochemistry, and rechargeable battery technology. Indeed, the determination of the hydration structures, dynamics, and dielectric properties of the NaF electrolyte in aqueous solutions is a crucial element in order to optimize its performance and predict its intervention mechanisms in industrial processes. In this study, we used the molecular dynamics approach to study the NaF(aq) binary system at different concentrations ranging from 0.1 to 1.0 mol.kg−1 using the OPLS-AA force field combined with the extended simple point load water model (SPC/E). Thus, the ions were represented as charged Lennard-Jones particles. The radial distribution functions (RDF) have been calculated to analyze the hydration shell structures of different ion pairs. The microstructures, self-diffusion coefficient, and dielectric constant were determined by molecular dynamics at various concentrations. Moreover, our FTIR spectroscopy data confirm the results obtained from molecular simulations.

An Update on Parkinson's Disease and its Neurodegenerative Counterparts.

Neurodegenerative disorders are a group of diseases that cause nerve cell degeneration in the brain, resulting in a variety of symptoms and are not treatable with drugs. Parkinson's disease (PD), prion disease, motor neuron disease (MND), Huntington's disease (HD), spinal cerebral dyskinesia (SCA), spinal muscle atrophy (SMA), multiple system atrophy, Alzheimer's disease (AD), spinocerebellar ataxia (SCA) (ALS), pantothenate kinase-related neurodegeneration, and TDP-43 protein disorder are examples of neurodegenerative diseases. Dementia is caused by the loss of brain and spinal cord nerve cells in neurodegenerative diseases. Even though environmental and genetic predispositions have also been involved in the process, redox metal abuse plays a crucial role in neurodegeneration since the preponderance of symptoms originates from abnormal metal metabolism. Hence, this review investigates several neurodegenerative diseases that may occur symptoms similar to Parkinson's disease to understand the differences and similarities between Parkinson's disease and other neurodegenerative disorders based on reviewing previously published papers. Based on the findings, the aggregation of alpha-synuclein occurs in Parkinson's disease, multiple system atrophy, and dementia with Lewy bodies. Other neurodegenerative diseases occur with different protein aggregation or mutations. We can conclude that Parkinson's disease, Multiple system atrophy, and Dementia with Lewy bodies are closely related. Therefore, researchers must distinguish among the three diseases to avoid misdiagnosis of Multiple System Atrophy and Dementia with Lewy bodies with Parkinson's disease symptoms.

ZTF J185259.31+124955.2: A new evolved disc-eclipsing binary system

Discs in long-period eclipsing binary systems are rare and can lead to extraordinary eclipsing events. ZTF J185259.31+124955.2 was identified as a candidate disc-eclipsing system through a continuing search programme of ZTF variables with a near-IR excess in the WISE data. Examination of the combined ZTF and ATLAS photometry shows seven eclipses since 2017 with depths of 0 in all bands on a period of $289.57 The eclipse width is $ 40$\,d but this and the profile evolve over time. Comparison with library spectra shows that the spectral energy distribution from the available photometry is consistent with an early K-type giant, and fitting black-body profiles suggests $ 4000$\,K for the stellar component, with a cool component having $ < 500$\,K. The reddening and distance, and hence the luminosity place the star within the giant branch. The most likely scenario is that the system is in a state of rapid evolution following Case B/C mass transfer into an extended disc around an unseen companion.

An experimental study of foam-oil interactions for nonionic-based binary surfactant systems under high salinity conditions

A key factor affecting foam stability is the interaction of foam with oil in the reservoir. This work investigates how different types of oil influence the stability of foams generated with binary surfactant systems under a high salinity condition. Foam was generated with binary surfactant systems, one composed of a zwitterionic and a nonionic surfactant, and the other composed of an anionic and a nonionic surfactant. Our results showed that the binary surfactant foams investigated are more tolerant under high salinity conditions and in the presence of oil. This was visually observed in our microscopic analysis and was further attributed to an increase in apparent viscosity achieved with binary surfactant systems, compared to single surfactant foams. To understand the influence of oil on foam stability, we performed a mechanistic study to investigate how these oils interact with foams generated with binary surfactants, focusing on their applicability under high salinity conditions. The generation and stability of foam are linked to the ability of the surfactant system to solubilize oil molecules. Oil droplets that solubilize in the micelles appear to destabilize the foam. However, oils with higher molecular weights are too large to be solubilized in the micelles, hence the molecules will have less ability to be transported out of the foam, so oil seems to stabilize the foam. Finally, we conducted a multivariate analysis to identify the parameters that influenced foam stability in different oil types, using the experimental data from our work. The results showed that the oil molecular weight, interfacial tension between the foaming liquid and the oil, and the spreading coefficient are the most important variables for explaining the variation in the data. By performing a partial least square regression, a linear model was developed based on these most important variables, which can be used to predict foam stability for subsequent experiments under the same conditions as our work.

Female Sports Journalists: The More Things Change, the More They Stay the Same

This article aims to explore the experiences of female sports journalists in Sweden from a gender perspective. The theoretical framework is inspired by Yvonne Hirdman’s understanding of gender in a binary system and R. W. Connell’s definition of hegemonic masculinity. Data consist of 10 semi-structured interviews with the most prominent female sports journalists in Sweden. The sports journalists in this study express that there has been a change in the media industry, resulting in a better understanding of women’s working conditions within the industry. Even so, the work is still grounded in a culture signified by hegemonic masculinity, where women need to find their own strategies to build a successful career, handle harassment, and cope with other gender-related challenges.

A review for Kepler-453 binary system and its giant planet

Kepler 453 is a binary with a G star and a red dwarf found by Kepler telescope in 2015, and it has a giant planet named Kepler 453b detected by eclipsing in light curves with the period of 240.5 days, which will be showed in part 2. Based on the researches for circumbinary systems, this paper also discusses the radiation and plasma environment and some possibility for other celestial bodies like Trojan, earth-like planets in habitable zone. The result shows that Trojan has a narrow appropriate zone while the earth-size planets will be ejected by the current giant in Kepler 453.

Local in Time Conservative Binary Dynamics at Fourth Post-Minkowskian Order

Leveraging scattering information to describe binary systems in generic orbits requires identifying local and nonlocal in time tail effects. We report here the derivation of the universal (nonspinning) local in time conservative dynamics at fourth post-Minkowskian order, i.e., O(G4). This is achtieved by computing the nonlocal-in-time contribution to the deflection angle, and removing it from the full conservative value in [C. Dlapa , .; C. Dlapa , .]. Unlike the total result, the integration problem involves two scales—velocity and mass ratio—and features multiple polylogarithms, complete elliptic and iterated elliptic integrals, notably in the mass ratio. We reconstruct the local radial action, center-of-mass momentum and Hamiltonian, as well as the exact logarithmic-dependent part(s), all valid for generic orbits. We incorporate the remaining nonlocal terms for ellipticlike motion to sixth post-Newtonian order. The combined Hamiltonian is in perfect agreement in the overlap with the post-Newtonian state of the art. The results presented here provide the most accurate description of gravitationally bound binaries harnessing scattering data to date, readily applicable to waveform modeling. Published by the American Physical Society 2024

Insights into the Distinct Behaviors between Bifunctional and Binary Organoborane Catalysts through Terpolymerization of Epoxide, CO2, and Anhydride

AbstractAlkyl borane compounds‐mediated polymerizations have expanded to Lewis pair polymerization, free radical polymerization, ionic ring‐opening polymerization, and polyhomologation. The bifunctional organoborane catalysts that contain the Lewis acid and ammonium or phosphonium salt in one molecule have demonstrated superior catalytic performance for ring‐opening polymerization of epoxides and ring‐opening copolymerization of epoxides and CO2 than their two‐component analogues, i.e., the blend of organoborane and ammonium or phosphonium salt. To explore the origin of the differences of the one‐component and two‐component organoborane catalysts, here we conducted a systematic investigation on the catalytic performances of these two kinds of organoborane catalysts via terpolymerization of epoxide, carbon dioxide and anhydride. The resultant terpolymers produced independently by bifunctional and binary organoborane catalyst exhibited distinct microstructures, where a series of gradient polyester‐polycarbonate terpolymers with varying polyester content were afforded using the bifunctional catalyst, while tapering diblock terpolymers were obtained using the binary system. The bifunctional catalyst enhances the competitiveness of CO2 insertion than anhydride, which leads to the premature incorporation of CO2 into the polymer chains and ultimately results in the formation of gradient terpolymers. DFT calculations revealed the role of electrostatic interaction and charge distribution caused by intramolecular synergistic effect for bifunctional organoborane catalyst.

Searching for OB-type pre-supernova binary companions inside supernova remnants

Abstract We searched for OB-runaway stars inside supernova remnants (SNRs) as a pre-supernova binary companion. As the majority of massive stars are found in close binary systems, a runaway star ejected by the orbital energy after the supernova (SN) is expected to be found. Considering a binary mass fraction, q=0.25 − 1.0, the runaway star is likely to have an OB spectral type. We selected 12 SNRs at Galactic longitudes 109○ − 189○. Using Gaia astrometry we selected stars having consistent distances with those of the SNRs and showing a peculiar proper motion directed away from the central region of the SNRs. We also determined the radial distribution of the extinction towards the SNRs and estimated the spectral types of the OB-runaway candidates through Gaia and 2MASS photometry. We found two candidates among 12 SNRs. By spectroscopic observations, Gaia DR3 195632152560621440 inside SNR G166.0+4.3 was found to be an evolved A3 type star which cannot be the pre-SN binary companion to the progenitor. Gaia DR3 513927750767375872 inside SNR HB 3 is the only OB-runaway candidate (2-D space velocity of 33.3±3.3 km s−1). Based on photometric study, the star can be an early B-type main sequence star with a slightly higher extinction relative to the SNR, however, it might instead be an evolved A-type star at the same distance. The other 11 SNRs do not host an OB-runaway star within their central regions. Although the runaway search was performed in a large interval of distance and extinction, we also estimated distances to the SNRs.

Evolution and final fate of massive post-common-envelope binaries

Mergers of neutron stars (NSs) and black holes (BHs) are nowadays observed routinely thanks to gravitational-wave (GW) astronomy. In the isolated binary-evolution channel, a common-envelope (CE) phase of a red supergiant (RSG) and a compact object is crucial to sufficiently shrink the orbit and thereby enable a merger via GW emission. Here, we use the outcomes of two three-dimensional (3D) magneto-hydrodynamic CE simulations of an initially 10.0 solar-mass RSG with a 5.0 solar-mass BH and a 1.4 solar-mass NS, respectively, to explore the further evolution and final fate of the remnant binaries (post-CE binaries). Notably, the 3D simulations reveal that the post-CE binaries are likely surrounded by circumbinary disks (CBDs), which contain substantial mass and angular momentum to influence the subsequent evolution. The binary systems in MESA modelling undergo another phase of mass transfer and we find that most donor stars do not explode in ultra-stripped supernovae (SNe), but rather in Type Ib/c SNe. Without NS kicks, the final orbital configurations of our models with the BH companion are too wide to allow for a compact object merger within a Hubble time. NS kicks are actually required to sufficiently perturb the orbit and thus facilitate a merger via GW emission. Moreover, we explore the influence of CBDs observed in 3D CE simulations on the evolution and final fate of the post-CE binaries. We find that mass accretion from the disk widens the binary orbit, while resonant interactions between the CBD and the binary can shrink the separation and increase the eccentricity of the binary depending on the disk mass and lifetime. Efficient resonant contractions may even enable a BH or NS to merge with the remnant He stars before a second SN explosion, which may be observed as gamma-ray burst-like transients, luminous fast blue optical transients, and Thorne-\.Zytkow objects. For the surviving post-CE binaries, the CBD-binary interactions may significantly increase the GW-induced double compact merger fraction. We conclude that accounting for CBD may be crucial to better understand observed GW mergers.

Search for giant planets in M 67 V: A warm Jupiter orbiting the turn-off star S1429

Context. Planets orbiting members of open or globular clusters offer a great opportunity to study exoplanet populations systematically, as stars within clusters provide a mostly homogeneous sample, at least in chemical composition and stellar age. However, even though there have been coordinated efforts to search for exoplanets in stellar clusters, only a small number of planets have been detected. One successful example is the seven-year radial velocity (RV) survey ‘Search for giant planets in M 67’ of 88 stars in the open cluster M 67, which led to the discovery of five giant planets, including three close-in (P < 10 days) hot-Jupiters. Aims. In this work, we continue and extend the observation of stars in M 67, with the aim being to search for additional planets. Methods. We conducted spectroscopic observations with the Habitable Planet Finder (HPF), HARPS, HARPS-North, and SOPHIE spectrographs of 11 stars in M 67. Six of our targets showed a variation or long-term trends in their RV during the original survey, while the other five were not observed in the original sample, bringing the total number of stars to 93. Results. An analysis of the RVs reveals one additional planet around the turn-off point star S1429 and provides solutions for the orbits of stellar companions around S2207 and YBP2018. S1429 b is a warm-Jupiter on a likely circular orbit with a period of $\[\77.48_{-0.19}^{+0.18}\]$ days and a minimum mass of M sin i = 1.80 ± 0.2 MJ. We update the hot-Jupiter occurrence rate in M 67 to include the five new stars, deriving $\[\4.2_{-2.3}^{+4.1} \%\]$ when considering all stars, and $\[\5.4_{-3.0}^{+5.1} \%\]$ if binary star systems are removed.

DIW-Printed Thermal Management PDMS Composites with 3D Structural Thermal Conductive Network of h-BN Platelets and Al2O3 Nanoparticles

Electronic devices play an increasingly vital role in modern society, and heat accumulation is a major concern during device development, which causes strong market demand for thermal conductivity materials and components. In this paper, a novel thermal conductive material consisting of polydimethylsiloxane (PDMS) and a binary filler system of h-BN platelets and Al2O3 nanoparticles was successfully fabricated using direct ink writing (DIW) 3D printing technology. The addictive manufacturing process not only endows the DIW-printed composites with various geometries but also promotes the construction of a 3D structural thermal conductive network through the shearing force during the printing process. Moreover, the integrity of the thermal conductive network can be optimized by filling the gaps between the BN platelets with Al2O3 particles. Resultingly, the configuration of the binary fillers is arranged by the shearing force during the DIW process, fabricating the thermal conductive network of oriented fillers. The DIW-printed BN/Al2O3/PDMS with 45 wt% thermal conductive binary filler can reach a thermal conductivity of 0.98 W/(m·K), higher than the 0.62 W/(m·K) of the control sample. In this study, a novel strategy for the thermal conductive performance improvement of composites based on DIW technology is successfully verified, paving a new way for thermal management.

Thermodynamics assessment of the Erbium-Ruthenium system by combining the Ab-initio and CALPHAD methods

ABSTRACT In the present study, the erbium-ruthenium system was optimised using the CALPHAD approach. The thermodynamic properties and the phase diagram were evaluated. The enthalpies of formation of the intermetallic compounds for the binary system Er-Ru were calculated by ab- initio methods. The liquid phase was treated with the exponential model, while a solution model was applied to represent the HCP (Er, Ru) solid solution. The five intermetallic compounds Er3Ru, Er5Ru2, Er3Ru2, ErRu2, and Er44Ru25 were considered as stoichiometric compounds. The calculations are in good agreement with the phase diagram information and experimental thermodynamic values documented in the literature.

Proposing a physical mechanism to explain various observed sources of QPOs by simulating the dynamics of accretion disks around the black holes

We propose a mechanism to explain the low-frequency QPOs observed in X-ray binary systems and AGNs. To achieve this, we perturbed stable accretion disks around Kerr and EGB black holes at different angular velocities, revealing characteristics of shock waves and oscillations on the disk. By applying this perturbation to scenarios with varying alpha values for EGB black holes and different spin parameters for Kerr black holes, we numerically observed changes in the disk dynamic structure and its oscillations. Through various numerical models, we found that the formation of one- and two-armed spiral shock waves on the disk serves as a mechanism for generating QPOs. We compared the QPOs obtained from numerical calculations with the low-frequency QPOs observed in X-ray binary systems and AGN sources, finding high consistency with observations. We observed that the shock mechanism, leading to QPOs, explains the X-ray binaries and AGNs studied in this article. Our numerical findings indicate that QPOs are more strongly dependent on the EGB constant than on the black hole spin parameter. However, we highlighted that the primary impact on oscillations and QPOs is driven by the perturbation angular velocity. The results from the models showed that the perturbation asymptotic speed at V∞=0.2\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$V_{\\infty }=0.2$$\\end{document} independently generates QPO frequencies, regardless of the black hole spin parameter and the EGB coupling constant. Therefore, for the moderate value of V∞\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$V_{\\infty }$$\\end{document}, a two-armed spiral shock wave formed around the black hole is suggested as a decisive mechanism in explaining low-frequency QPOs.

Precise Mass, Orbital Motion, and Stellar Properties of the M-dwarf Binary LP 349−25AB

LP 349−25 is a well-studied close stellar binary system comprised of two late M dwarf stars, where both stars are close to the limit between star and brown dwarf. This system was previously identified as a source of gigahertz radio emission. We observed LP 349−25AB over 11 epochs in 2020–2022, detecting both components in this nearby binary system using the Very Long Baseline Array (VLBA). We fit simultaneously the VLBA absolute astrometric positions together with existing relative astrometric observations derived from optical/infrared observations with a set of algorithms that use nonlinear least-squares, genetic algorithm, and Markov Chain Monte Carlo methods to determine the orbital parameters of the two components. We find the masses of the primary and secondary components to be 0.08188 ± 0.00061 M ⊙ and 0.06411 ± 0.00049 M ⊙, respectively, representing one of the most precise mass estimates of any ultracool dwarf (UCD) to date. The primary is a UCD of 85.71 ± 0.64 M Jup, while the secondary has a mass consistent with being a brown dwarf of 67.11 ± 0.51 M Jup. This is one of the very few direct detections of a brown dwarf with VLBA observations. We also find a distance to the binary system of 14.122 ± 0.057 pc. Using stellar evolutionary models, we find the model-derived stellar parameters of both stars. In particular, we obtain a model-derived age of 262 Myr for the system, which indicates that LP 349−25AB is composed of two pre–main-sequence stars. In addition, we find that the secondary star is significantly less evolved than the primary star.

Predicting the Stability of Formulations Containing Lyophilized Human Serum Albumin and Sucrose/Trehalose Using Solid-State NMR Spectroscopy.

Stabilization of proteins by disaccharides in lyophilized formulations depends on the interactions between the protein and the disaccharide (system homogeneity) and the sufficiently low mobility of the system. Human serum albumin (HSA) was lyophilized with disaccharides (sucrose and/or trehalose) in different relative concentrations. Solid-state nuclear magnetic resonance (ssNMR) spectroscopy 1H T1 and 1H T1ρ relaxation times were measured to determine the homogeneity of the lyophilized systems on 20-50 and 1-3 nm domains, respectively, with 1H T1 relaxation times also being used to determine the β-relaxation rate. HSA/sucrose systems had longer 1H T1 relaxation times and were slightly more stable than HSA/trehalose systems in almost all cases shown. HSA/sucrose/trehalose systems have 1H T1 relaxation times between the HSA/sucrose and HSA/trehalose systems and did not result in a more stable system compared with binary systems. Inhomogeneity was evident in a sample containing relative concentrations of 10% HSA and 90% trehalose, suggesting trehalose crystallization during lyophilization. Under these stability conditions and with these ssNMR acquisition parameters, a 1H T1 relaxation time below 1.5 s correlated with an unstable sample, regardless of the disaccharide(s) used.

Simultaneous Photometric and Spectroscopic Analysis of V505 Lacertae, a Photospherically and Chromospherically Active Contact Binary Star

New BVR photometric and high-resolution spectroscopic observations of V505 Lac are presented with Transiting Exoplanet Survey Satellite (TESS) photometric data. The orbital period has experienced a secular decrease during the past 16 yr. A clear anticorrelation in the primary and secondary eclipse timing variation (PSETV) obtained from the TESS data is also identified. A double-lined radial velocity (RV) curve is secured, and the effective temperatures of the less- and more-massive stars (Stars 1 and 2, respectively) are measured. Using a spectral subtraction technique, excess emissions are detected in the time-series Ca ii H and K and Hα lines for Star 2. Simultaneous analysis of the light and RV curves using the Wilson–Devinney (WD) code reveals that V505 Lac is a photospherically and chromospherically active W-subtype contact binary system. The component-star masses and radii are determined to an accuracy of approximately 1%. The WD spot model is individually applied to 221 light curves segmented from the TESS data so as to derive the spot parameters of a cool spot on Star 2. The combined variations in both longitude and colatitude among the spot parameters appear to be strongly associated with those of both the anticorrelation in the PSETV and the O’Connell effect in the TESS light curves. Robust negative linear relationships between the PSETV anticorrelation size and the O’Connell effect magnitude are found for the first time. Mass–radius, mass–luminosity, and mass ratio–mass diagrams of contact binaries, along with the mass ratio frequency distribution, are presented in an attempt to elucidate the evolutionary characteristics of these systems.

Thermally emitting isolated neutron star candidates from the SRG/eROSITA All-Sky Survey

The SRG/eROSITA All-Sky Survey (eRASS) allows for the creation of a complete sample of X-ray dim isolated neutron stars (XDINSs), which will significantly facilitate the study of their population properties, evolution, and connection to other families of isolated neutron stars (INSs). In this work, we conduct a systematic search for XDINSs on the eROSITA western Galactic hemisphere down to an X-ray flux limit of 10$^ and discuss the resulting candidate sample. Consistently with the properties of the known XDINSs, we selected all eRASS sources possessing a soft X-ray spectral distribution and that are unlikely to be associated with optical or infrared sources. Our selection criteria allowed us to recover all known XDINSs and previously proposed candidates. In addition, we put forward 33 new candidate members for dedicated follow-up identification campaigns. We found the resulting candidate sample to be about 30 -- 50<!PCT!> complete, mainly due to source confusion and the stringent cross-matching criteria adopted to select the most promising candidates for immediate follow-up investigation. The candidates of the sample presented here can be broadly divided into two groups: 13 rather soft and 20 hot and somewhat hard X-ray emitters. Interestingly, the remarkably thermal nature of the candidates in the first group as well as their spatial distribution, lack of known counterparts, and absence of significant flux variability agree well with the properties of other confirmed thermally emitting INSs. For the candidates in the second group, the current observational data do not allow one to discern between rotation-powered or recycled pulsars, cataclysmic variables, or quiescent neutron stars in binary systems or even to rule out an extragalactic nature. On the basis of population synthesis and the estimated source completeness of the search, we expect that between one and three new XDINSs are among the already singled-out list of XDINS candidates -- a long-sought increase in the proposed number of members of this elusive class of X-ray emitters.

Separation and purification of Ag and Se via vacuum thermal decomposition-volatilization of Ag2Se

In this study, theoretical and experimental investigations of the green separation and purification of Ag and Se from Ag2Se are conducted under vacuum. The vacuum separation theory calculation results indicate that the vapor pressure of Se is significantly higher than those of Ag and Ag2Se. Furthermore, the separation coefficient of the Se-Ag binary system is in the range of 104–105, and the Se content in the vapor phase exceeds 99.99 wt%. In contrast, the theoretical calculation results of vacuum thermal decomposition show that Ag2Se decomposes to Se2 (g) and Ag (l) at 1326.74 and 1488.21 K when the pressures are 1 and 10 Pa, respectively. The vacuum separation and purification experiments demonstrate that the purity of Se in the volatiles reaches 97.22 wt% at 1523 K, 50 Pa, and 480 min, and the main phase is the pure Se phase. Moreover, the purity of Ag in the residue reaches 91.88 wt%, and the main phase is the pure Ag phase. The vacuum thermal decomposition-volatilization proposed in this study can achieve environmentally friendly, short separation and purification of Ag and Se in Ag2Se.

Combined effect of Poynting-Robertson (P-R) drag, oblateness and radiation on the triangular points in the elliptic restricted three-body problem

This study investigates the motion of a test particle around triangular equilibrium points in the elliptic restricted three-body problem (ER3BP) under the influence of the two oblate and radiating primaries having Poynting-Robertson (P-R) drag. It is observed that the position of triangular points of the problem is affected by oblateness, radiation pressure, eccentricity, semi-major axis and Poynting-Robertson (P-R) drag. The stability of these points is demonstrated analytically by the Routh-Hurwitz criterion. It is seen that they are unstable under the combined effect of involved parameters. The effect of these parameters on the position of triangular points is examined numerically using the binary systems, 61 Cygni and Archird. The results obtained by these binary systems can be used to broaden the scope of interest in astronomy, astrophysics, space science and celestial mechanics in general.