Pub Date : 2025-11-04DOI: 10.1016/j.newast.2025.102482
Annarien G. Headley , James O. Chibueze
We investigated the distributions of classified young stellar object (YSO) in nine star-forming regions associated with Hii regions, namely Sh2-22, Sh2-19, Sh2-17, M16, M8, IC5070, Sh2-252, NGC2467 and M42, as a means of exploring the star formation scenarios (triggered or spontaneous) in the various regions. The YSO distributions of nine regions along the galactic longitudes and across different spiral arms were explored. It is noted that Sh2-22 and Sh2-19 may have evidence of localized triggered star formation, whereas Sh2-17 may be a spontaneous star forming region. The results showed that the location within the Milky Way may influence localized triggered star formation within individual regions. There is strong evidence that there are fewer older stars (Transition Disks) within the Outer regions of the Galaxy (), accompanied by a higher number of Class I (). This is different from the Inner Galactic regions where the Transition Disks are higher () as compared to low Class I sources (). The number of Class II stars is relatively high and increases from the Inner regions () to Outer regions (). These nine star-forming regions are not an accurate representation of locations throughout the Galaxy and the results may be biased.
{"title":"Investigating star formation scenarios in the Milky Way using YSO distributions—A pilot study","authors":"Annarien G. Headley , James O. Chibueze","doi":"10.1016/j.newast.2025.102482","DOIUrl":"10.1016/j.newast.2025.102482","url":null,"abstract":"<div><div>We investigated the distributions of classified young stellar object (YSO) in nine star-forming regions associated with <span>Hii</span> regions, namely Sh2-22, Sh2-19, Sh2-17, M16, M8, IC5070, Sh2-252, NGC2467 and M42, as a means of exploring the star formation scenarios (triggered or spontaneous) in the various regions. The YSO distributions of nine regions along the galactic longitudes and across different spiral arms were explored. It is noted that Sh2-22 and Sh2-19 may have evidence of localized triggered star formation, whereas Sh2-17 may be a spontaneous star forming region. The results showed that the location within the Milky Way may influence localized triggered star formation within individual regions. There is strong evidence that there are fewer older stars (Transition Disks) within the Outer regions of the Galaxy (<span><math><mrow><mn>2</mn><mo>.</mo><mn>91</mn><mo>±</mo><mn>1</mn><mo>.</mo><mn>74</mn><mtext>%</mtext></mrow></math></span>), accompanied by a higher number of Class I (<span><math><mrow><mn>32</mn><mo>.</mo><mn>49</mn><mo>±</mo><mn>10</mn><mo>.</mo><mn>77</mn><mtext>%</mtext></mrow></math></span>). This is different from the Inner Galactic regions where the Transition Disks are higher (<span><math><mrow><mn>32</mn><mo>.</mo><mn>93</mn><mo>±</mo><mn>13</mn><mo>.</mo><mn>78</mn><mtext>%</mtext></mrow></math></span>) as compared to low Class I sources (<span><math><mrow><mn>11</mn><mo>.</mo><mn>01</mn><mo>±</mo><mn>4</mn><mo>.</mo><mn>81</mn><mtext>%</mtext></mrow></math></span>). The number of Class II stars is relatively high and increases from the Inner regions (<span><math><mrow><mn>52</mn><mo>.</mo><mn>64</mn><mo>±</mo><mn>10</mn><mo>.</mo><mn>07</mn><mtext>%</mtext></mrow></math></span>) to Outer regions (<span><math><mrow><mn>64</mn><mo>.</mo><mn>54</mn><mo>±</mo><mn>11</mn><mo>.</mo><mn>09</mn><mtext>%</mtext></mrow></math></span>). These nine star-forming regions are not an accurate representation of locations throughout the Galaxy and the results may be biased.</div></div>","PeriodicalId":54727,"journal":{"name":"New Astronomy","volume":"123 ","pages":"Article 102482"},"PeriodicalIF":2.1,"publicationDate":"2025-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145520959","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-01DOI: 10.1016/j.newast.2025.102493
Abdelhakim Benkrane
We investigate the gravitational instability of self-gravitating systems characterized by the Plummer sphere profile. Using Jeans analysis, we derive modified expressions for the Jeans mass and Jeans radius, revealing that the presence of the Plummer radius increases both critical parameters, thereby suppressing gravitational collapse. In the classical regime, we obtain a modified dispersion relation incorporating the Fourier transform of the Plummer potential. Our results show that reduces the growth rate of perturbations and shifts the critical wavenumber to lower values, favoring the development of instability at longer wavelengths. We also extend the analysis to the quantum regime, where quantum pressure introduces a stabilizing -term in the dispersion relation. We find that at large wave numbers, quantum effects dominate and the influence of the becomes negligible. These findings highlight the role of Plummer sphere profile in modulating the onset and scale of gravitational collapse, with implications for star formation and structure formation in dark matter (DM)-rich environments.
{"title":"Gravitational instability in Plummer sphere profile: A Jeans analysis","authors":"Abdelhakim Benkrane","doi":"10.1016/j.newast.2025.102493","DOIUrl":"10.1016/j.newast.2025.102493","url":null,"abstract":"<div><div>We investigate the gravitational instability of self-gravitating systems characterized by the Plummer sphere profile. Using Jeans analysis, we derive modified expressions for the Jeans mass and Jeans radius, revealing that the presence of the Plummer radius <span><math><msub><mrow><mi>r</mi></mrow><mrow><mn>0</mn></mrow></msub></math></span> increases both critical parameters, thereby suppressing gravitational collapse. In the classical regime, we obtain a modified dispersion relation incorporating the Fourier transform of the Plummer potential. Our results show that <span><math><msub><mrow><mi>r</mi></mrow><mrow><mn>0</mn></mrow></msub></math></span> reduces the growth rate of perturbations and shifts the critical wavenumber to lower values, favoring the development of instability at longer wavelengths. We also extend the analysis to the quantum regime, where quantum pressure introduces a stabilizing <span><math><msup><mrow><mi>k</mi></mrow><mrow><mn>4</mn></mrow></msup></math></span>-term in the dispersion relation. We find that at large wave numbers, quantum effects dominate and the influence of the <span><math><msub><mrow><mi>r</mi></mrow><mrow><mn>0</mn></mrow></msub></math></span> becomes negligible. These findings highlight the role of Plummer sphere profile in modulating the onset and scale of gravitational collapse, with implications for star formation and structure formation in dark matter (DM)-rich environments.</div></div>","PeriodicalId":54727,"journal":{"name":"New Astronomy","volume":"123 ","pages":"Article 102493"},"PeriodicalIF":2.1,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145469089","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-01DOI: 10.1016/j.newast.2025.102484
Xu-Zhi Li , Xue-Tong Liu , Wei Liu , Xu-Dong Zhang
Contact binary stars are crucial for studying stellar evolution and merger events, but precise determination of their physical parameters (mass ratio , inclination , fill-out factor ) is challenging. While large-scale, single-band surveys coupled with machine learning enable rapid population studies, discrepancies arise between solutions derived from such automated pipelines due to inherent degeneracies and limited wavelength constraints. In this work, we resolve the conflicting parameters reported for contact binary system NSVS 4803568 through comprehensive multi-band photometric observations. We conducted follow-up , , , and -band observations and analyzed the light curves using PHOEBE, refined via Markov Chain Monte Carlo. Our solution confirms the system as a W-subtype contact binary and reveals a significant third-light contribution. The parameter inconsistencies between single-band studies highlight limitations in machine learning training data sensitivity and the need for multi-dimensional flux constraints. We advocate a hybrid approach: machine learning pre-screening of survey data to identify high-priority targets (e.g., extreme or short period systems) followed by multi-band validation to calibrate models and mitigate systematic errors. This synergy is essential for unlocking the full potential of astronomical big data in stellar astrophysics.
{"title":"Calibrating machine learning with multi-band photometry: Resolving parameter degeneracies in contact binary NSVS 4803568","authors":"Xu-Zhi Li , Xue-Tong Liu , Wei Liu , Xu-Dong Zhang","doi":"10.1016/j.newast.2025.102484","DOIUrl":"10.1016/j.newast.2025.102484","url":null,"abstract":"<div><div>Contact binary stars are crucial for studying stellar evolution and merger events, but precise determination of their physical parameters (mass ratio <span><math><mi>q</mi></math></span>, inclination <span><math><mi>i</mi></math></span>, fill-out factor <span><math><mi>f</mi></math></span>) is challenging. While large-scale, single-band surveys coupled with machine learning enable rapid population studies, discrepancies arise between solutions derived from such automated pipelines due to inherent degeneracies and limited wavelength constraints. In this work, we resolve the conflicting parameters reported for contact binary system NSVS 4803568 through comprehensive multi-band photometric observations. We conducted follow-up <span><math><mi>B</mi></math></span>, <span><math><mi>V</mi></math></span>, <span><math><mi>R</mi></math></span>, and <span><math><mi>I</mi></math></span>-band observations and analyzed the light curves using PHOEBE, refined via Markov Chain Monte Carlo. Our solution confirms the system as a W-subtype contact binary and reveals a significant third-light contribution. The parameter inconsistencies between single-band studies highlight limitations in machine learning training data sensitivity and the need for multi-dimensional flux constraints. We advocate a hybrid approach: machine learning pre-screening of survey data to identify high-priority targets (e.g., extreme <span><math><mi>q</mi></math></span> or short period systems) followed by multi-band validation to calibrate models and mitigate systematic errors. This synergy is essential for unlocking the full potential of astronomical big data in stellar astrophysics.</div></div>","PeriodicalId":54727,"journal":{"name":"New Astronomy","volume":"123 ","pages":"Article 102484"},"PeriodicalIF":2.1,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145469090","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-01DOI: 10.1016/j.newast.2025.102492
Pius Privatus , Umananda Dev Goswami
Bars are fundamental structures in disc galaxies, although their role in galaxy evolution is still not fully known. This study investigates the effect of the presence of bars on the environmental dependence of disc galaxies’ properties using the volume-limited sample from Mapping Nearby Galaxies at APO (MaNGA) survey. The disc galaxies with and without bars samples were obtained using the Galaxy Zoo 2 project then assigned into isolated and non-isolated sub-samples. These sub-samples were used to compare the stellar mass, star formation rate, colour, concentration index and gas phase metallicity, and their relationships between isolated and non-isolated environments. Then these are used to investigate if there is an existence of any difference between galaxies with and without bars. A one-to-one correspondence between isolated and non-isolated galaxy properties was observed, and a strong dependence on the environment for properties of unbarred galaxies was observed when compared to barred. The stellar mass against star formation rate, colour against concentration index and stellar mass against gas phase metallicity of unbarred galaxies strongly depend on environment while for barred these relations weakly depend on environment. The study concludes that bars in disc galaxies decrease the dependence of analysed properties and their relations on the environment.
{"title":"Analysis of the effect of bars on environmental dependence of disc galaxies with MaNGA survey data","authors":"Pius Privatus , Umananda Dev Goswami","doi":"10.1016/j.newast.2025.102492","DOIUrl":"10.1016/j.newast.2025.102492","url":null,"abstract":"<div><div>Bars are fundamental structures in disc galaxies, although their role in galaxy evolution is still not fully known. This study investigates the effect of the presence of bars on the environmental dependence of disc galaxies’ properties using the volume-limited sample from Mapping Nearby Galaxies at APO (MaNGA) survey. The disc galaxies with and without bars samples were obtained using the Galaxy Zoo 2 project then assigned into isolated and non-isolated sub-samples. These sub-samples were used to compare the stellar mass, star formation rate, <span><math><mrow><mi>g</mi><mo>−</mo><mi>r</mi></mrow></math></span> colour, concentration index and gas phase metallicity, and their relationships between isolated and non-isolated environments. Then these are used to investigate if there is an existence of any difference between galaxies with and without bars. A one-to-one correspondence between isolated and non-isolated galaxy properties was observed, and a strong dependence on the environment for properties of unbarred galaxies was observed when compared to barred. The stellar mass against star formation rate, <span><math><mrow><mi>g</mi><mo>−</mo><mi>r</mi></mrow></math></span> colour against concentration index and stellar mass against gas phase metallicity of unbarred galaxies strongly depend on environment while for barred these relations weakly depend on environment. The study concludes that bars in disc galaxies decrease the dependence of analysed properties and their relations on the environment.</div></div>","PeriodicalId":54727,"journal":{"name":"New Astronomy","volume":"123 ","pages":"Article 102492"},"PeriodicalIF":2.1,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145469125","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-30DOI: 10.1016/j.newast.2025.102485
Nilanjana Dey Choudhury , P. Shalima , Keerthana U. , J. Murthy
Far-Ultraviolet (FUV) halos have been detected around six bright stars by Murthy and Henry (2011) using GALEX observations. These halos are thought to be caused by forward scattering of the starlight by dust grains present in thin foreground clouds. The optical constants of grains producing such halos have been constrained earlier by using a single scattering model, that considered the Henyey-Greenstein empirical phase function instead of theoretical phase functions for the scattering grains. In this work, we have modelled the FUV halos for two stars, Spica and Achernar, by considering the realistic porous aggregates of different sizes and compositions. As the Henyey-Greenstein phase function is known to deviate from theoretical predictions, we have utilized theoretical scattering phase functions for modelling. The dust is placed in a double-layered plane-parallel sheet with its distance and optical depth varied to get the best fit. We find that the halo intensities are dominated by scattering due to sized porous dust aggregates made of amorphous silicate and carbonaceous aggregates for Spica and Achernar, respectively. We find that the medium in front of Achernar has a lower optical depth () of 0.032 compared to Spica which has a value of = 0.1. This low value is close to the optical depth of the local ISM (0.01) within 40 pc of the Sun. This study demonstrates an effective method to constrain the dust grain properties in the local interstellar medium.
{"title":"Modelling the scattering by porous aggregate dust grains in the Far-Ultraviolet halos of Spica and Achernar","authors":"Nilanjana Dey Choudhury , P. Shalima , Keerthana U. , J. Murthy","doi":"10.1016/j.newast.2025.102485","DOIUrl":"10.1016/j.newast.2025.102485","url":null,"abstract":"<div><div>Far-Ultraviolet (FUV) halos have been detected around six bright stars by Murthy and Henry (2011) using GALEX observations. These halos are thought to be caused by forward scattering of the starlight by dust grains present in thin foreground clouds. The optical constants of grains producing such halos have been constrained earlier by using a single scattering model, that considered the Henyey-Greenstein empirical phase function instead of theoretical phase functions for the scattering grains. In this work, we have modelled the FUV halos for two stars, Spica and Achernar, by considering the realistic porous aggregates of different sizes and compositions. As the Henyey-Greenstein phase function is known to deviate from theoretical predictions, we have utilized theoretical scattering phase functions for modelling. The dust is placed in a double-layered plane-parallel sheet with its distance and optical depth varied to get the best fit. We find that the halo intensities are dominated by scattering due to <span><math><mrow><mn>0</mn><mo>.</mo><mn>05</mn><mspace></mspace><mi>μ</mi><mi>m</mi></mrow></math></span> sized porous dust aggregates made of amorphous silicate and carbonaceous aggregates for Spica and Achernar, respectively. We find that the medium in front of Achernar has a lower optical depth (<span><math><mi>τ</mi></math></span>) of 0.032 compared to Spica which has a value of <span><math><mi>τ</mi></math></span> = 0.1. This low value is close to the optical depth of the local ISM (0.01) within 40 pc of the Sun. This study demonstrates an effective method to constrain the dust grain properties in the local interstellar medium.</div></div>","PeriodicalId":54727,"journal":{"name":"New Astronomy","volume":"123 ","pages":"Article 102485"},"PeriodicalIF":2.1,"publicationDate":"2025-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145420230","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-17DOI: 10.1016/j.newast.2025.102483
Yiqi Wu (吴艺琪) , Simon Portegies Zwart , Henk A. Dijkstra
Planetary obliquity (axial tilt) plays an important role in regulating the climate evolution and habitability of water-covered planets. Despite the suspicion of large obliquities in several exoplanetary systems, this phenomenon remains hard to observe directly.
We aimed to study the effect of mass, obliquity, and rotation on the steady state climate of water-covered planets. We simulated the climate evolution of such planets with varying obliquities, rotational speed, and mass using a general circulation model (GCM) of intermediate complexity, assuming aqua-planet configurations.
High obliquity supports an asymmetry between the equilibrium climatological conditions in the northern and southern hemispheres. The polar temperature ratio deviates further from unity with increasing obliquity and rotation rate. Cloud coverage patterns also shift with obliquity, displaying distinct latitudinal bands and increased cloudiness in the warmer hemisphere.
The climate of habitable-zone aqua-planets turns out to be sensitive to changes in obliquity and rotation rate, but are independent of planet mass. Our results highlight the importance of considering these factors when assessing the surface conditions of exoplanets. As a consequence, surface condition asymmetries in water-world exo-planets can be used to infer the planet’s obliquity and rotation rate.
{"title":"A systematic north-south asymmetry in the steady-state climate of rapidly-rotating oblique water worlds","authors":"Yiqi Wu (吴艺琪) , Simon Portegies Zwart , Henk A. Dijkstra","doi":"10.1016/j.newast.2025.102483","DOIUrl":"10.1016/j.newast.2025.102483","url":null,"abstract":"<div><div>Planetary obliquity (axial tilt) plays an important role in regulating the climate evolution and habitability of water-covered planets. Despite the suspicion of large obliquities in several exoplanetary systems, this phenomenon remains hard to observe directly.</div><div>We aimed to study the effect of mass, obliquity, and rotation on the steady state climate of water-covered planets. We simulated the climate evolution of such planets with varying obliquities, rotational speed, and mass using a general circulation model (GCM) of intermediate complexity, assuming aqua-planet configurations.</div><div>High obliquity supports an asymmetry between the equilibrium climatological conditions in the northern and southern hemispheres. The polar temperature ratio deviates further from unity with increasing obliquity and rotation rate. Cloud coverage patterns also shift with obliquity, displaying distinct latitudinal bands and increased cloudiness in the warmer hemisphere.</div><div>The climate of habitable-zone aqua-planets turns out to be sensitive to changes in obliquity and rotation rate, but are independent of planet mass. Our results highlight the importance of considering these factors when assessing the surface conditions of exoplanets. As a consequence, surface condition asymmetries in water-world exo-planets can be used to infer the planet’s obliquity and rotation rate.</div></div>","PeriodicalId":54727,"journal":{"name":"New Astronomy","volume":"123 ","pages":"Article 102483"},"PeriodicalIF":2.1,"publicationDate":"2025-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145420229","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-10DOI: 10.1016/j.newast.2025.102481
Srinivas M. Rao , Jeewan C. Pandey , Nikita Rawat , Arti Joshi , Ajay Kumar Singh
Utilizing high-cadence and long-term optical photometry from the Transiting Exoplanet Survey Satellite (TESS), we conducted a time-resolved timing analysis of the Intermediate Polar, V709 Cas. Our analysis reveals key characteristics of this system: an orbital period of 5.3329 ± 0.0002 h, a spin period of 312.7478 ± 0.0002 s, and a beat period of 317.9267 ± 0.0002 s. These periods represent a significant refinement over the results of previous studies. These analyses demonstrate that V709 Cas is primarily a disc-overflow accretor, with accretion predominantly occurring via a disc. However, the analysis also reveals epochs where stream-fed accretion is a dominant accretion process. Time-resolved analysis of 20 s short cadence data obtained from sectors 57 and 58 reveals the presence of distinct first harmonics of the spin and beat frequencies. This finding indicates the presence of double peak spin modulation, a characteristic signature of two-pole accretion onto the white dwarf.
{"title":"Long-term optical photometry of V709 Cas using TESS: Refined periods and accretion geometry","authors":"Srinivas M. Rao , Jeewan C. Pandey , Nikita Rawat , Arti Joshi , Ajay Kumar Singh","doi":"10.1016/j.newast.2025.102481","DOIUrl":"10.1016/j.newast.2025.102481","url":null,"abstract":"<div><div>Utilizing high-cadence and long-term optical photometry from the Transiting Exoplanet Survey Satellite (<em>TESS</em>), we conducted a time-resolved timing analysis of the Intermediate Polar, V709 Cas. Our analysis reveals key characteristics of this system: an orbital period of 5.3329 ± 0.0002 h, a spin period of 312.7478 ± 0.0002 s, and a beat period of 317.9267 ± 0.0002 s. These periods represent a significant refinement over the results of previous studies. These analyses demonstrate that V709 Cas is primarily a disc-overflow accretor, with accretion predominantly occurring via a disc. However, the analysis also reveals epochs where stream-fed accretion is a dominant accretion process. Time-resolved analysis of 20 s short cadence data obtained from sectors 57 and 58 reveals the presence of distinct first harmonics of the spin and beat frequencies. This finding indicates the presence of double peak spin modulation, a characteristic signature of two-pole accretion onto the white dwarf.</div></div>","PeriodicalId":54727,"journal":{"name":"New Astronomy","volume":"122 ","pages":"Article 102481"},"PeriodicalIF":2.1,"publicationDate":"2025-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145333144","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-03DOI: 10.1016/j.newast.2025.102480
M. Javed Idrisi, Ruchi Gupta
This study investigates the dynamics of a test particle under the influence of two primaries in the framework of the Yukawa-type radiating restricted three-body problem (YR3BP). The model incorporates two significant perturbations to the classical circular restricted three-body problem (CR3BP): radiation pressure from the larger primary and a Yukawa-type correction to the Newtonian gravitational potential. We first identify the existence and linear stability of out-of-plane equilibrium points, which arise when the radiation pressure exceeds the gravitational pull of the radiating primary. These equilibrium points are found to be independent of the Yukawa parameters, suggesting that the Yukawa-type force does not influence their locations. We also calculate families of three-dimensional periodic (halo-type) and quasi-periodic orbits around these stable equilibrium points using numerical simulations. Our results underline how radiation and modified gravity shape the behaviour of small bodies in disturbed celestial environments, as well as the rich orbital structures that the YR3BP model supports.
{"title":"Out-of-plane equilibria in the Yukawa-type radiating restricted three-body problem (YR3BP)","authors":"M. Javed Idrisi, Ruchi Gupta","doi":"10.1016/j.newast.2025.102480","DOIUrl":"10.1016/j.newast.2025.102480","url":null,"abstract":"<div><div>This study investigates the dynamics of a test particle under the influence of two primaries in the framework of the Yukawa-type radiating restricted three-body problem (YR3BP). The model incorporates two significant perturbations to the classical circular restricted three-body problem (CR3BP): radiation pressure from the larger primary and a Yukawa-type correction to the Newtonian gravitational potential. We first identify the existence and linear stability of out-of-plane equilibrium points, which arise when the radiation pressure exceeds the gravitational pull of the radiating primary. These equilibrium points are found to be independent of the Yukawa parameters, suggesting that the Yukawa-type force does not influence their locations. We also calculate families of three-dimensional periodic (halo-type) and quasi-periodic orbits around these stable equilibrium points using numerical simulations. Our results underline how radiation and modified gravity shape the behaviour of small bodies in disturbed celestial environments, as well as the rich orbital structures that the YR3BP model supports.</div></div>","PeriodicalId":54727,"journal":{"name":"New Astronomy","volume":"122 ","pages":"Article 102480"},"PeriodicalIF":2.1,"publicationDate":"2025-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145266334","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-09-30DOI: 10.1016/j.newast.2025.102479
Luis J. Goicoechea , Vyacheslav N. Shalyapin
The quadruply-imaged gravitationally lensed quasar PS J0147+4630 at redshift 2 is a good candidate for time delay cosmography and microlensing-based source structure studies. In this paper, new spectra of its four images are derived from archive data of two 10-m class telescopes. We focus on the unexplored near-IR spectral region including the Mg ii, H, [O iii] and H emission lines (0.9), and measure image flux ratios for the emission lines and their underlying continua, as well as a reliable quasar redshift of 2.357 ± 0.002. We also find evidence of an outflow in the H emission and estimate a quasar black-hole logarithmic mass = 9.34 ± 0.30.
{"title":"Near-IR spectroscopy of the gravitationally lensed quasar PS J0147+4630","authors":"Luis J. Goicoechea , Vyacheslav N. Shalyapin","doi":"10.1016/j.newast.2025.102479","DOIUrl":"10.1016/j.newast.2025.102479","url":null,"abstract":"<div><div>The quadruply-imaged gravitationally lensed quasar PS J0147+4630 at redshift <span><math><mrow><mi>z</mi><mo>></mo></mrow></math></span> 2 is a good candidate for time delay cosmography and microlensing-based source structure studies. In this paper, new spectra of its four images are derived from archive data of two 10-m class telescopes. We focus on the unexplored near-IR spectral region including the Mg<!--> <span>ii</span>, H<span><math><mi>β</mi></math></span>, [O<!--> <span>iii</span>] and H<span><math><mi>α</mi></math></span> emission lines (0.9<span><math><mrow><mo>−</mo><mn>2</mn><mo>.</mo><mn>4</mn><mspace></mspace><mi>μ</mi><mi>m</mi></mrow></math></span>), and measure image flux ratios for the emission lines and their underlying continua, as well as a reliable quasar redshift of 2.357 ± 0.002. We also find evidence of an outflow in the H<span><math><mi>α</mi></math></span> emission and estimate a quasar black-hole logarithmic mass <span><math><mrow><mo>log</mo><mfenced><mrow><msub><mrow><mi>M</mi></mrow><mrow><mi>BH</mi></mrow></msub><mo>/</mo><msub><mrow><mi>M</mi></mrow><mrow><mo>⊙</mo></mrow></msub></mrow></mfenced></mrow></math></span> = 9.34 ± 0.30.</div></div>","PeriodicalId":54727,"journal":{"name":"New Astronomy","volume":"122 ","pages":"Article 102479"},"PeriodicalIF":2.1,"publicationDate":"2025-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145227244","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-09-29DOI: 10.1016/j.newast.2025.102478
Lin-yan Jiang , Li-yun Zhang , Xianming L. Han , Prabhakar Misra , Josh Wanninger , Hong-peng Lu , Qing-Feng Pi , Jun-Tao Wan
<div><div>We obtained new light curves of two eclipsing binaries 1SWASP J075102.16+342405.3 and CP Psc on eleven nights from 2013 to 2017 using two optical telescopes. We analyzed the orbital period variation using all collected minima, including our eleven new minima. We found that the periods of the systems J075102 and CP Psc are increasing at rates of <span><math><mrow><mover><mrow><mi>p</mi></mrow><mrow><mo>̇</mo></mrow></mover><mo>=</mo><mo>+</mo><mn>2</mn><mo>.</mo><mn>55</mn><mrow><mo>(</mo><mn>3</mn><mo>)</mo></mrow><mo>×</mo><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mo>−</mo><mn>7</mn></mrow></msup></mrow></math></span> days/yr and <span><math><mrow><mover><mrow><mi>p</mi></mrow><mrow><mo>̇</mo></mrow></mover><mo>=</mo><mo>+</mo><mn>6</mn><mo>.</mo><mn>32</mn><mrow><mo>(</mo><mn>8</mn><mo>)</mo></mrow><mo>×</mo><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mo>−</mo><mn>8</mn></mrow></msup></mrow></math></span> days/yr, respectively. Subsequently, we updated the orbital parameters of J075102 using the Wilson–Devinney program and obtained the orbital parameters of CP Psc for the first time. The result shows that J075102 is an contact binary with the contact factor of <span><math><mrow><mi>f</mi><mo>=</mo><mn>28</mn><mo>.</mo><mn>64</mn><mrow><mo>(</mo><mo>±</mo><mn>0</mn><mo>.</mo><mn>03</mn><mo>)</mo></mrow><mtext>%</mtext></mrow></math></span>, the mass ratio <span><math><mrow><mi>q</mi><mo>=</mo><msub><mrow><mi>M</mi></mrow><mrow><mn>2</mn></mrow></msub><mo>/</mo><msub><mrow><mi>M</mi></mrow><mrow><mn>1</mn></mrow></msub></mrow></math></span> of 1.9, the mass as <span><math><mrow><msub><mrow><mi>M</mi></mrow><mrow><mn>1</mn></mrow></msub><mo>=</mo><mn>0</mn><mo>.</mo><mn>766</mn><msub><mrow><mi>M</mi></mrow><mrow><mo>⊙</mo></mrow></msub></mrow></math></span>, <span><math><mrow><msub><mrow><mi>M</mi></mrow><mrow><mn>2</mn></mrow></msub><mo>=</mo><mn>1</mn><mo>.</mo><mn>459</mn><msub><mrow><mi>M</mi></mrow><mrow><mo>⊙</mo></mrow></msub></mrow></math></span>, the mass transfer from the secondary component to the primary component of <span><math><mrow><msub><mrow><mover><mrow><mi>M</mi></mrow><mrow><mo>̇</mo></mrow></mover></mrow><mrow><mn>2</mn></mrow></msub><mo>=</mo><mo>−</mo><mn>6</mn><mo>.</mo><mn>59</mn><mo>×</mo><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mo>−</mo><mn>7</mn></mrow></msup><msub><mrow><mi>M</mi></mrow><mrow><mo>⊙</mo></mrow></msub></mrow></math></span>/<span><math><mrow><mi>y</mi><mi>e</mi><mi>a</mi><mi>r</mi></mrow></math></span>. For CP Psc, we conducted a simultaneous analysis of our light curves and spectroscopic observations obtained by LAMOST. The spectral type determined by the LAMOST stellar spectra survey was approximately G3. The results indicate that it is a detached binary star system composed of <span><math><mrow><msub><mrow><mi>M</mi></mrow><mrow><mn>1</mn></mrow></msub><mo>=</mo><mn>0</mn><mo>.</mo><mn>940</mn><msub><mrow><mi>M</mi></mrow><mrow><mo>⊙</mo></mrow></msub></mrow></math></span> and <spa
{"title":"Photometric studies of the Short-period Eclipsing Binary J075102.16+342405.3 and CP Psc","authors":"Lin-yan Jiang , Li-yun Zhang , Xianming L. Han , Prabhakar Misra , Josh Wanninger , Hong-peng Lu , Qing-Feng Pi , Jun-Tao Wan","doi":"10.1016/j.newast.2025.102478","DOIUrl":"10.1016/j.newast.2025.102478","url":null,"abstract":"<div><div>We obtained new light curves of two eclipsing binaries 1SWASP J075102.16+342405.3 and CP Psc on eleven nights from 2013 to 2017 using two optical telescopes. We analyzed the orbital period variation using all collected minima, including our eleven new minima. We found that the periods of the systems J075102 and CP Psc are increasing at rates of <span><math><mrow><mover><mrow><mi>p</mi></mrow><mrow><mo>̇</mo></mrow></mover><mo>=</mo><mo>+</mo><mn>2</mn><mo>.</mo><mn>55</mn><mrow><mo>(</mo><mn>3</mn><mo>)</mo></mrow><mo>×</mo><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mo>−</mo><mn>7</mn></mrow></msup></mrow></math></span> days/yr and <span><math><mrow><mover><mrow><mi>p</mi></mrow><mrow><mo>̇</mo></mrow></mover><mo>=</mo><mo>+</mo><mn>6</mn><mo>.</mo><mn>32</mn><mrow><mo>(</mo><mn>8</mn><mo>)</mo></mrow><mo>×</mo><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mo>−</mo><mn>8</mn></mrow></msup></mrow></math></span> days/yr, respectively. Subsequently, we updated the orbital parameters of J075102 using the Wilson–Devinney program and obtained the orbital parameters of CP Psc for the first time. The result shows that J075102 is an contact binary with the contact factor of <span><math><mrow><mi>f</mi><mo>=</mo><mn>28</mn><mo>.</mo><mn>64</mn><mrow><mo>(</mo><mo>±</mo><mn>0</mn><mo>.</mo><mn>03</mn><mo>)</mo></mrow><mtext>%</mtext></mrow></math></span>, the mass ratio <span><math><mrow><mi>q</mi><mo>=</mo><msub><mrow><mi>M</mi></mrow><mrow><mn>2</mn></mrow></msub><mo>/</mo><msub><mrow><mi>M</mi></mrow><mrow><mn>1</mn></mrow></msub></mrow></math></span> of 1.9, the mass as <span><math><mrow><msub><mrow><mi>M</mi></mrow><mrow><mn>1</mn></mrow></msub><mo>=</mo><mn>0</mn><mo>.</mo><mn>766</mn><msub><mrow><mi>M</mi></mrow><mrow><mo>⊙</mo></mrow></msub></mrow></math></span>, <span><math><mrow><msub><mrow><mi>M</mi></mrow><mrow><mn>2</mn></mrow></msub><mo>=</mo><mn>1</mn><mo>.</mo><mn>459</mn><msub><mrow><mi>M</mi></mrow><mrow><mo>⊙</mo></mrow></msub></mrow></math></span>, the mass transfer from the secondary component to the primary component of <span><math><mrow><msub><mrow><mover><mrow><mi>M</mi></mrow><mrow><mo>̇</mo></mrow></mover></mrow><mrow><mn>2</mn></mrow></msub><mo>=</mo><mo>−</mo><mn>6</mn><mo>.</mo><mn>59</mn><mo>×</mo><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mo>−</mo><mn>7</mn></mrow></msup><msub><mrow><mi>M</mi></mrow><mrow><mo>⊙</mo></mrow></msub></mrow></math></span>/<span><math><mrow><mi>y</mi><mi>e</mi><mi>a</mi><mi>r</mi></mrow></math></span>. For CP Psc, we conducted a simultaneous analysis of our light curves and spectroscopic observations obtained by LAMOST. The spectral type determined by the LAMOST stellar spectra survey was approximately G3. The results indicate that it is a detached binary star system composed of <span><math><mrow><msub><mrow><mi>M</mi></mrow><mrow><mn>1</mn></mrow></msub><mo>=</mo><mn>0</mn><mo>.</mo><mn>940</mn><msub><mrow><mi>M</mi></mrow><mrow><mo>⊙</mo></mrow></msub></mrow></math></span> and <spa","PeriodicalId":54727,"journal":{"name":"New Astronomy","volume":"122 ","pages":"Article 102478"},"PeriodicalIF":2.1,"publicationDate":"2025-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145267106","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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