We have investigated the relation between the orbital period P<SUB>orb</SUB> and the spin period P<SUB>s</SUB> of neutron stars in OB/X-ray binaries. By simulating the time-development of the m...We have investigated the relation between the orbital period P<SUB>orb</SUB> and the spin period P<SUB>s</SUB> of neutron stars in OB/X-ray binaries. By simulating the time-development of the mass loss rate and radius expansion of a 20M<SUB>☉</SUB> donor star, we have calculated the detailed spin evolution of the neutron star before steady wind accretion occurs (that is, when the break spin period is reached), or when the OB star begins evolving off the main sequence or has filled its Roche lobe. Our results are compatible with the observations of OB/X-ray binaries. We find that in relatively narrow systems with orbital periods less than tens of days, neutron stars with initial magnetic field B<SUB>0</SUB> stronger than about 3×10<SUP>12</SUP> G can reach the break spin period to allow steady wind accretion in the main sequence time, whereas neutron stars with B<SUB>0</SUB> < 3×10<SUP>12</SUP> G and/or in wide systems would still be in one of the pulsar, rapid rotator or propeller phases when the companion evolves off the main sequence or fills its Roche lobe. Our results may help understand the various characteristics of the observed OB/neutron star binaries along with their distributions in the P<SUB>s</SUB>-P<SUB>orb</SUB> diagram.展开更多
Photometric observations are presented in V and I bands of six eclipsing binaries at the lower limit of the orbital periods for W UMa stars. Three of them are newly discovered eclipsing systems. The light curve soluti...Photometric observations are presented in V and I bands of six eclipsing binaries at the lower limit of the orbital periods for W UMa stars. Three of them are newly discovered eclipsing systems. The light curve solutions reveal that all shortperiod targets are contact or overcontact binaries and six new binaries are added to the family of short-period systems with estimated parameters. Four binaries have com- ponents that are equal in size and a mass ratio near 1. The phase variability shown by the V-I colors of all targets may be explained by lower temperatures on their back surfaces than those on their side surfaces. Five systems exhibit the O＇Connell effect that can be modeled by cool spots on the side surfaces of their primary components. The light curves of V1067 Her in 2011 and 2012 are fitted by diametrically opposite spots. Applying the criteria for subdivision of W UMa stars to our targets leads to ambiguous results.展开更多
Based on positional observations and measurements of radial velocities,the orbits of 850 wide visual binary stars have been determined.The parameters of the log-normal distributions for the histograms of orbital perio...Based on positional observations and measurements of radial velocities,the orbits of 850 wide visual binary stars have been determined.The parameters of the log-normal distributions for the histograms of orbital periods,stellar masses,and semimajor axes in astronomical units have been obtained.The eccentricity histogram for binary stars with orbital periods less than 400 yr follows a normal distribution centered at e=0.545+/−0.029.For stars with longer periods,this distribution obeys the law f=2e,with accuracy to errors.The mass-to-luminosity relation for stars with well-determined masses is given by:log L_(⊙)=4.33 logM_(⊙)-0.11,where L_(⊙) and M_(⊙) are the luminosity and mass of the star in units of the solar luminosity and mass,respectively.展开更多
Binary systems in the asymptotic giant branch(AGB)phase are widely recognized as a leading theoretical framework underpinning the observed asymmetric morphologies of planetary nebulae.However,the detection of binary c...Binary systems in the asymptotic giant branch(AGB)phase are widely recognized as a leading theoretical framework underpinning the observed asymmetric morphologies of planetary nebulae.However,the detection of binary companions in AGB systems is severely hampered by the overwhelming brightness and variability of the evolved primary star,which dominates the photometric and spectroscopic signatures.Ultraviolet(UV)excess emission has been proposed as a candidate diagnostic for the presence of binary companions in AGB systems.This paper evaluates the Chinese Space Station Telescope’s(CSST)ability to detect UV excess emission in AGB stars,leveraging its unprecedented UV sensitivity and wide-feld survey capabilities.We employed synthetic spectral libraries of M0–M8 type giants for primary stars and the ATLAS 9 atmospheric model grid for companion stars spanning a temperature range of 6500 to 12,000 K.By convolving these model spectra with the CSST multi-band flter system,we computed color–color diagrams(g–y versus NUV–u)to construct a diagnostic grid.This grid incorporates interstellar extinction corrections and establishes a framework for identifying AGB binary candidates through direct comparison between observed photometry and theoretical predictions.Furthermore,we discuss the physical origins of UV excess in AGB stars.This study pioneers a diagnostic framework leveraging CSST’s unique multi-band UV-visible synergy to construct color–color grids for binary candidate identifcation,overcoming limitations of non-simultaneous multi-instrument observations.展开更多
We present the results of our study of the long-period eclipsing binary star V454 Aur.The results are based on spectroscopic data obtained with the UFESéchelle spectrograph and photometric observations from Trans...We present the results of our study of the long-period eclipsing binary star V454 Aur.The results are based on spectroscopic data obtained with the UFESéchelle spectrograph and photometric observations from Transiting Exoplanet Survey Satellite(TESS).The derived radial velocity curve is based on 17 spectra obtained between 2021and 2023,covering all orbital phases of this binary system.The orbital period determined from TESS data,P=27.019803±0.000003 days,agrees within uncertainties with the period established in previous studies.The model constructed for the TESS photometric light curve achieves a precision of 0.01%.The effective temperatures of both components,as well as the system metallicity,were directly derived from the spectra and are Teff,A=6250±50 K,Teff,B=5855±50 K,and[Fe/H]=-0.10±0.08,respectively.Our analysis of the photometric and spectroscopic data allowed us to directly compute the luminosities of the components,LA=1.82 L☉and LB=1.07 L☉,their radii,RA=1.15 R☉and RB=1.00 R☉,and their masses,MA=1.137 M☉and MB=1.023 M☉,with uncertainties below 1%.Comparison with evolutionary tracks indicates that the system’s age is 1.18±0.10 Gyr,and both components are still on the main sequence.The V454 Aur system is particularly interesting due to the partial eclipse of the primary component,which results in the“inversion”of the primary and secondary minima in the photometric light curve.展开更多
With the advancement of astronomical observation technology,people have a deeper understanding of the formation and evolution of galaxies,but many details of our own Milky Way and other external galaxies are still unk...With the advancement of astronomical observation technology,people have a deeper understanding of the formation and evolution of galaxies,but many details of our own Milky Way and other external galaxies are still unknown.Therefore,by studying the formation and orbital transformation mechanism of satellites,planets and stars,the author puts forward a new theory on the formation and evolution of stars and galaxies,thus revealing the hierarchical structure of galaxies and the formation and evolution laws of main sequence stars,red giants,white dwarfs,black dwarfs,supernovae,neutron stars,black holes and quasars.Some special phenomena in the course of star formation and evolution,such as sunspots,flares,fast radio bursts and gamma-ray bursts,have also been revealed.展开更多
In this paper,new light curve fitting and orbital period change analysis of two contact binaries NSVS 9023048 and NSVS 2461789 are presented.We found that both of them are totally eclipsing contact binaries.Our photom...In this paper,new light curve fitting and orbital period change analysis of two contact binaries NSVS 9023048 and NSVS 2461789 are presented.We found that both of them are totally eclipsing contact binaries.Our photometric solutions suggest that NSVS 9023048 is a deep contact binary(q=10.14,f=69.2%),however,NSVS 2461789is a shallow one(f=24.4%,q=3.08).The asymmetric light curves of NSVS 2461789 and NSVS 9023048 can be explained by the star-spot activity.At the same time,using the available eclipse times,we first studied the orbital period changes of these two targets.It is discovered that the period of NSVS 9023048 is decreasing at a rate of dP/dt=-1.17×10^(-6)day yr^(-1),which can be explained by mass transfer from the more massive star to the less massive one or angular momentum loss.In addition,the O-C diagrams of NSVS 9023048 and NSVS 2461789show possible cyclic oscillations with a period of 7.29 yr and 9.91 yr,respectively.The cyclic oscillations may be caused by the light-travel time effect due to the presence of a third component.The mass of the tertiary companion is determined to be M_(3)sin(i_(3))=9.05 Mefor NSVS 9023048 and M_(3)sin(i_(3))=0.11 Mefor NSVS 2461789.Based on our calculations,the third body of NSVS 9023048 may be a black hole candidate.Our study also reveals that NSVS 9023048 is stable now.展开更多
In this study,the apsidal motion analyses of the eclipsing binary systems V398 Lac,V2544 Cyg,and V785 Cas are presented.The(O-C)diagrams of the selected systems were constructed using all available and reliable times ...In this study,the apsidal motion analyses of the eclipsing binary systems V398 Lac,V2544 Cyg,and V785 Cas are presented.The(O-C)diagrams of the selected systems were constructed using all available and reliable times of minimum light compiled from the literature.As a result,the apsidal motion periods were determined to be 353±50 yr,43.3±5.1 yr and 83.4±8.5 yr,respectively.Furthermore,the TESS light curves of the three systems were analyzed to derive their photometric and absolute parameters.The component masses were determined as follows:for V398 Lac,M_(1)=3.83±0.35 M_(⊙)and M2=3.27±0.35 M_(⊙);for V2544 Cyg,M_(1)=1.75±0.38 M_(⊙)and M2=1.40±0.38 M_(⊙);for V785 Cas,M_(1)=5.64±0.41 M_(⊙)and M2=5.18±0.41 M_(⊙).The parameters related to apsidal motion,as well as the observational and theoretical internal structure constants(K_(2,obs) and K_(2,teo))were calculated for studied binaries.The relativistic contribution to the observed apsidal motion rate was found to be relatively small,constituting less than approximately 5%of the total rate in each system.The theoretical internal structure constants were derived from the evolutionary models,assuming a standard chemical composition of(X,Z)=(0.70,0.01).展开更多
The emission of anomalous X-ray pulsars(AXPs)and soft gamma-ray repeaters(SGRs)is believed to be powered by the dissipation of their strong magnetic fields,which coined the name“magnetar”.By combining timing and ene...The emission of anomalous X-ray pulsars(AXPs)and soft gamma-ray repeaters(SGRs)is believed to be powered by the dissipation of their strong magnetic fields,which coined the name“magnetar”.By combining timing and energy observational results,the magnetar model can be easily appreciated.From a timing perspective,the magnetic field strengths of AXPs and SGRs,which are calculated under the assumption of dipole radiation,are extremely strong.From an energy perspective,the X-ray/soft gamma-ray luminosities of AXPs and SGRs are larger than their rotational energy loss rates(i.e.,L_(x>E_(rot)).It is thus reasonable to assume that the high-energy radiation comes from magnetic energy decay,and the magnetar model has been extensively discussed(or accepted).However,we argue that:(ⅰ)Calculating magnetic fields by assuming that rotational energy loss is dominated by dipole radiation(i.e.,E_(rot)■E_(μ))may be controversial,and we suggest that the energies carried by outflowing particles should also be considered.(ⅱ)The fact that X-ray luminosity is greater than the rotational energy loss rate does not necessarily mean that the emission energy comes from the magnetic field decaying,which requires further observational testing.Furthermore,some observational facts conflict with the“magnetar”model,such as observations of anti-magnetars,high magnetic field pulsars,and radio and X-ray observations of AXPs/SGRs.Therefore,we propose a crusted strange star model as an alternative,which can explain many more observational facts of AXPs/SGRs.展开更多
We present a theoretical model for detecting axions from neutron stars in a QCD phase of quark matter. The axions would be produced from a quark-antiquark pair uu¯or dd¯, in loop(s) involving gluons. The chi...We present a theoretical model for detecting axions from neutron stars in a QCD phase of quark matter. The axions would be produced from a quark-antiquark pair uu¯or dd¯, in loop(s) involving gluons. The chiral anomaly of QCD and the spontaneously broken symmetry are invoked to explain the non-conservation of the axion current. From the coupling form factors, the axion emissivities ϵacan be derived, from which fluxes can be determined. We predict a photon flux, which may be detectable by Fermi LAT, and limits on the QCD mass ma. In this model, axions decay to gamma rays in a 2-photon vertex. We may determine the expected fluxes from the theoretical emissivity. The sensitivity curve from the Fermi Large Area Telescope (Fermi LAT) would allow axion mass constraints for neutron stars as low as ma≤10−14eV 95% C.L. Axions could thus be detectable in gamma rays for neutron stars as distant as 100 kpc. A signal from LIGO GWS 170817 could be placed from the NS-NS merger, which gives an upper limit of ma≤10−10eV.展开更多
With a one-dimensional stellar evolution model,we find that massive main sequence stars can accrete mass at very high mass accretion rates without expanding much if they lose a significant fraction of this mass from t...With a one-dimensional stellar evolution model,we find that massive main sequence stars can accrete mass at very high mass accretion rates without expanding much if they lose a significant fraction of this mass from their outer layers simultaneously with mass accretion.We assume the accretion process is via an accretion disk that launches powerful jets from its inner zones.These jets remove the outer high-entropy layers of the mass-accreting star.This process operates in a negative feedback cycle,as the jets remove more envelope mass when the star expands.With the one-dimensional model,we mimic the mass removal by jets by alternating mass addition and mass removal phases.For the simulated models of 30M☉and 60M☉,the star does not expand much if we remove more than about half of the added mass in not-too-short episodes.This holds even if we deposit the energy the jets do not carry into the envelope.As the star does not expand much,its gravitational potential well stays deep,and the jets are energetic.These results are relevant to bright transient events of binary systems powered by accretion and the launching of jets,e.g.,intermediate luminosity optical transients,including some luminous red novae,the grazing envelope evolution,and the 1837–1856 Great Eruption of Eta Carinae.展开更多
The best way to check the validity of our theories(models)is by direct comparison with the experiment(observations).However,this process suffers from numerical inaccuracies,which are not frequently studied and often r...The best way to check the validity of our theories(models)is by direct comparison with the experiment(observations).However,this process suffers from numerical inaccuracies,which are not frequently studied and often remain mostly unknown.In this study,we focus on addressing the numerical inaccuracies intrinsic to the process of comparing theory and observations.To achieve this goal,we built four-dimensional(4D)spectral grids for Wolf–Rayet stars(WC and WN spectral classes)and blue supergiants characterized by low metallicity similar to that of the Small Magellanic Cloud.In contrast to lighter(three-dimensional)grids,which rely on a priori assumptions about certain stellar parameters(e.g.,wind velocity)and thus have limited applicability,our 4D grids vary four independent parameters,enabling more flexible and broadly applicable spectral fitting.Utilizing these 4D grids,we developed and validated a fitting approach facilitating direct fits to observed spectra.Through rigorous testing on designated“test”models,we demonstrated that the numerical precision of derived essential stellar parameters,including effective temperature,mass-loss rate,luminosity,and wind velocity,is better than 0.05 dex.Furthermore,we explored the influence of unaccounted factors,including variations in the metal abundances,wind acceleration laws,and clumping,on the precision of the derived parameters.The results indicate that the first two factors have the strongest influence on the numerical accuracy of the derived stellar parameters.Variations in abundances predominantly influenced the mass-loss rate for weak-wind scenarios,while effective temperature and luminosity remained robust.We found that the wind acceleration law influences the numerical uncertainty of the derived wind parameters mostly for models with weak winds.Interestingly,different degrees of clumping demonstrated good precision for spectra with strong winds,contrasting with a decrease in the precision for weak-wind cases.We found also that the accuracy of our approach depends on spectral range and the inclusion of ultraviolet spectral range improves the precision of derived parameters,especially for an object with weak winds.展开更多
Stars can form and evolve within gaseous disks around active galactic nuclei(AGNs).In the sub-parsec region of disks around~10~8M_(☉)black holes,stars accrete rapidly,reaching■200 M_(☉)and settling into a quasi-ste...Stars can form and evolve within gaseous disks around active galactic nuclei(AGNs).In the sub-parsec region of disks around~10~8M_(☉)black holes,stars accrete rapidly,reaching■200 M_(☉)and settling into a quasi-steady state in which accretion balances wind-driven mass loss.Within this environment,their ultimate fate depends critically on the radiative-zone diffusion coefficient(Dmix),which encapsulates various mixing processes and governs chemical transport between surface and core.Using the MESA stellar evolution code,we simulate AGN stars across a range of mixing efficiencies.We find a critical threshold floor value D_(mix,min)≈1010 cm~2 s^(-1)that separates two distinct fates:1."Immortal stars"—when mixing is over-efficient(D_(mix,min)■10^(10)cm~2 s^(-1)),rapid hydrogen replenishment sustains core hydrogen burning,maintains main-sequence equilibrium,rendering the star effectively“immortal.”2."Metamorphic stars"—when mixing is merely efficient(D_(mix,min)<1010 cm~2 s^(-1)),stars exhaust core hydrogen,evolve off-main-sequence,shed mass to≈15 M_(☉),and produce super-solar a-abundances consistent with AGN observations.We conclude that maintaining a mixing floor below this threshold is sufficient to avoid immortality,as flux-induced extra mixing can be effectively modeled via constant floor values.Our estimates provide a foundation for future work on disk enrichment and stellar evolution.展开更多
Accurate determinations of metallicity for large,complete stellar samples are essential for advancing various studies of the Milky Way.In this paper,we present a data-driven algorithm that leverages photometric data f...Accurate determinations of metallicity for large,complete stellar samples are essential for advancing various studies of the Milky Way.In this paper,we present a data-driven algorithm that leverages photometric data from the KiDS and the VIKING surveys to estimate stellar absolute magnitudes,effective temperatures,and metallicities.The algorithm is trained and validated using spectroscopic data from LAMOST,SEGUE,APOGEE,and GALAH,as well as a catalog of very metal-poor stars from the literature,and Gaia EDR3 data.This approach enables us to estimate metallicities,effective temperatures,and g-band absolute magnitudes for approximately 0.8 million stars in the KiDS data set.The photometric metallicity estimates exhibit an uncertainty of around 0.28 dex when compared to spectroscopic studies,within the metallicity range of−2 dex to 0.5 dex.The photometric effective temperature estimates have an uncertainty of around 149 K,while the uncertainty in the absolute magnitudes is approximately 0.36 mag.The metallicity estimates are reliable for values down to about−2 dex.This catalog represents a valuable resource for studying the structure and chemical properties of the Milky Way,offering an extensive data set for future investigations into Galactic formation and evolution.展开更多
The subsurface convective zones (CZs) of massive stars significantly influence many of their key characteristics.Previous studies have paid little attention to the impact of rotation on the subsurface CZ,so we aim to ...The subsurface convective zones (CZs) of massive stars significantly influence many of their key characteristics.Previous studies have paid little attention to the impact of rotation on the subsurface CZ,so we aim to investigate the evolution of this zone in rapidly rotating massive stars.We use the Modules for Experiments in Stellar Astrophysics to simulate the subsurface CZs of massive stars during the main sequence phase.We establish stellar models with initial masses ranging from 5 M⊙to 120 M⊙,incorporating four metallicities (Z=0.02,0.006,0.002,and 0.0001) and three rotational velocities (ω/ωcrit=0,ω/ωcrit=0.50,andω/ωcrit=0.75).We find that rapid rotation leads to an expansion of the subsurface CZ,increases convective velocities,and promotes the development of this zone.Additionally,subsurface CZs can also emerge in stars with lower metallicities.Comparing our models with observations of massive stars in the Galaxy,the Large Magellanic Cloud,and the Small Magellanic Cloud,we find that rotating models better encompass the observed samples.Rotation significantly influences the evolution of the subsurface CZ in massive stars.By comparing with the observed microturbulence on the surfaces of OB stars,we propose that the subsurface CZs may be one of the sources of microturbulence.展开更多
Red clump(RC)stars are reliable standard candles for studying the structure and evolution of the Milky Way.In this study,we present empirical calibrations of RC absolute magnitudes in the Mephisto(v,g,r,i)and CSST(g,r...Red clump(RC)stars are reliable standard candles for studying the structure and evolution of the Milky Way.In this study,we present empirical calibrations of RC absolute magnitudes in the Mephisto(v,g,r,i)and CSST(g,r,i)photometric systems using a high-purity sample of 25,059 RC stars cross-matched between APOGEE and Gaia DR3 XP spectra.Through synthetic photometry and polynomial fitting,we find that RC absolute magnitudes exhibit strong dependencies on effective temperature and metallicity,with the strongest variations observed in bluer bands and progressively decreasing towards redder wavelengths.In particular,the Mephisto v band exhibits the highest sensitivity,with variations reaching up to 2.0 mag across the metallicity range(−1.0 dex<[Fe/H]<0.5 dex)and the temperature range(4500–5200 K).The calibrations achieve high precision for all bands,enabling accurate determination of RC absolute magnitudes and distances.Furthermore,we evaluate the metallicity estimation capabilities of both systems using a Random Forest-based method,achieving a precision of 0.12 dex for Mephisto and 0.14 dex for CSST under typical photometric uncertainties(≤0.01 mag).These results provide robust tools for distance and metallicity determinations,supporting future Galactic structure studies with Mephisto and CSST data.展开更多
The study of carbon-enhanced metal-poor (CEMP) stars is of great significance for understanding the chemical evolution of the early universe and stellar formation.CEMP stars are characterized by carbon overabundance a...The study of carbon-enhanced metal-poor (CEMP) stars is of great significance for understanding the chemical evolution of the early universe and stellar formation.CEMP stars are characterized by carbon overabundance and are classified into several subclasses based on the abundance patterns of neutron-capture elements,including CEMP-s,CEMP-no,CEMP-r,and CEMP-r/s.These subclasses provide important insights into the formation of thefirst stars,early stellar nucleosynthesis,and supernova explosions.However,one of the major challenges in CEMP star research is the relatively small sample size of identified stars,which limits statistical analyses and hinders a comprehensive understanding of their properties.Fortunately,a series of large-scale spectroscopic survey projects have been launched and developed in recent years,providing unprecedented opportunities and technical challenges for the search and study of CEMP stars.To this end,this paper draws on the progress and future prospects of existing methods in constructing large CEMP data sets and offers an in-depth discussion from a technical standpoint,focusing on the strengths and limitations.In addition,we review recent advancements in the identification of CEMP stars,emphasizing the growing role of machine learning in processing and analyzing the increasingly large data sets generated by modern astronomical surveys.Compared to traditional spectral analysis methods,machine learning offers greater efficiency in handling complex data,automatic extraction of stellar parameters,and improved prediction accuracy.Despite these advancements,the research faces persistent challenges,including the scarcity of labeled samples,limitations imposed by low-resolution spectra,and the lack of interpretability in machine learning models.To address these issues,the paper proposes potential solutions and future research directions aimed at advancing the study of CEMP stars and enhancing our understanding of their role in the chemical evolution of the universe.展开更多
In the present article,we introduce a completely new regular model for static,spherically symmetric celestial fluid spheres in embedding classⅠspacetime.In this regard,needfully,we propose a new suitable metric poten...In the present article,we introduce a completely new regular model for static,spherically symmetric celestial fluid spheres in embedding classⅠspacetime.In this regard,needfully,we propose a new suitable metric potential e^(λ(r))to generate the present model.The various analyses on energy density,pressure,anisotropic factor,mass,compactness parameter,redshift,and energy condition make sure the model is physically viable on the ground of model stars Vela X-1,Cen X-3,SMC X-4,and LMC X-4.The reported solutions also respect the equilibrium state by satisfying the Tolman-Oppenheimer-Volkoff(TOV)equation and ensure stability by satisfying the causality condition,condition on the adiabatic index,and Harrison-Zeldovich-Novikov condition.The generated M-R graph matches the ranges of masses and radii for the model compact stars.Additionally,this study provides estimates of the moment of inertia based on the I-M graph.展开更多
在2025釜山国际广告节New Stars全球青年创意竞赛的领奖台上,来自省广集团的苏粤与搭档吕一潇的欢呼格外响亮。这对因连续几次在比赛中获得银奖而自我调侃为“千年老二”的搭档,终于以《THE AI ACCESS CARD》的创意作品拿下金奖。她们...在2025釜山国际广告节New Stars全球青年创意竞赛的领奖台上,来自省广集团的苏粤与搭档吕一潇的欢呼格外响亮。这对因连续几次在比赛中获得银奖而自我调侃为“千年老二”的搭档,终于以《THE AI ACCESS CARD》的创意作品拿下金奖。她们的故事藏着新一代广告人对创意、行业与技术的思考。展开更多
δScuti(δSct)stars are potential distance tracers for studying the Milky Way structure.We conduct a comprehensive analysis of the period-luminosity(PL)and period-luminosity-metallicity(PLZ)relations forδSct stars,in...δScuti(δSct)stars are potential distance tracers for studying the Milky Way structure.We conduct a comprehensive analysis of the period-luminosity(PL)and period-luminosity-metallicity(PLZ)relations forδSct stars,integrating data from the Zwicky Transient Facility,the Transiting Exoplanet Survey Satellite,Large Sky Area Multi-Object Fiber Spectroscopic Telescope,Apache Point Observatory Galactic Evolution Experiment,and Gaia.To mitigate the impact of the Gaia parallax zero point offset,we applied a correction method,determining the optimal zero point value to be zp(?)=35±2μas.Using the three best bands,by varying the parallax error threshold,we found that the total error of the PLR zero point was minimized to 0.9%at a parallax error threshold of 6%.With this threshold,we derived the PL and PLZ relations for nine bands(from optical to mid-infrared)and five Wesenheit bands.Through our analysis,we conclude that the influence of metallicity on the PLR ofδSct stars is not significant,and the differences across various bands are minimal.展开更多
基金Supported by the National Natural Science Foundation of China.
文摘We have investigated the relation between the orbital period P<SUB>orb</SUB> and the spin period P<SUB>s</SUB> of neutron stars in OB/X-ray binaries. By simulating the time-development of the mass loss rate and radius expansion of a 20M<SUB>☉</SUB> donor star, we have calculated the detailed spin evolution of the neutron star before steady wind accretion occurs (that is, when the break spin period is reached), or when the OB star begins evolving off the main sequence or has filled its Roche lobe. Our results are compatible with the observations of OB/X-ray binaries. We find that in relatively narrow systems with orbital periods less than tens of days, neutron stars with initial magnetic field B<SUB>0</SUB> stronger than about 3×10<SUP>12</SUP> G can reach the break spin period to allow steady wind accretion in the main sequence time, whereas neutron stars with B<SUB>0</SUB> < 3×10<SUP>12</SUP> G and/or in wide systems would still be in one of the pulsar, rapid rotator or propeller phases when the companion evolves off the main sequence or fills its Roche lobe. Our results may help understand the various characteristics of the observed OB/neutron star binaries along with their distributions in the P<SUB>s</SUB>-P<SUB>orb</SUB> diagram.
基金partly supported by funds provided by projects RD 02-263 administered by the Scientific Foundation of Shumen Universitya joint project of the University of Massachusetts and the Infrared Processing and Analysis Center/California Institute of Technology+1 种基金funded by the National Aeronautics and Space Administrationthe National Science Foundation
文摘Photometric observations are presented in V and I bands of six eclipsing binaries at the lower limit of the orbital periods for W UMa stars. Three of them are newly discovered eclipsing systems. The light curve solutions reveal that all shortperiod targets are contact or overcontact binaries and six new binaries are added to the family of short-period systems with estimated parameters. Four binaries have com- ponents that are equal in size and a mass ratio near 1. The phase variability shown by the V-I colors of all targets may be explained by lower temperatures on their back surfaces than those on their side surfaces. Five systems exhibit the O＇Connell effect that can be modeled by cool spots on the side surfaces of their primary components. The light curves of V1067 Her in 2011 and 2012 are fitted by diametrically opposite spots. Applying the criteria for subdivision of W UMa stars to our targets leads to ambiguous results.
基金support of the Russian Foundation for Basic Research under Contract No.20-02-00563A.
文摘Based on positional observations and measurements of radial velocities,the orbits of 850 wide visual binary stars have been determined.The parameters of the log-normal distributions for the histograms of orbital periods,stellar masses,and semimajor axes in astronomical units have been obtained.The eccentricity histogram for binary stars with orbital periods less than 400 yr follows a normal distribution centered at e=0.545+/−0.029.For stars with longer periods,this distribution obeys the law f=2e,with accuracy to errors.The mass-to-luminosity relation for stars with well-determined masses is given by:log L_(⊙)=4.33 logM_(⊙)-0.11,where L_(⊙) and M_(⊙) are the luminosity and mass of the star in units of the solar luminosity and mass,respectively.
基金supports of this work are from the science research grants from the China Manned Space Project(NOs.CMSCSST-2021-A09,CMS-CSST-2021-A10,etc.)the National Natural Science Foundation of China(NSFC,Nos.12473027 and 12333005)the Guangdong Basic and Applied Basic Research Funding(No.2024A1515010798).
文摘Binary systems in the asymptotic giant branch(AGB)phase are widely recognized as a leading theoretical framework underpinning the observed asymmetric morphologies of planetary nebulae.However,the detection of binary companions in AGB systems is severely hampered by the overwhelming brightness and variability of the evolved primary star,which dominates the photometric and spectroscopic signatures.Ultraviolet(UV)excess emission has been proposed as a candidate diagnostic for the presence of binary companions in AGB systems.This paper evaluates the Chinese Space Station Telescope’s(CSST)ability to detect UV excess emission in AGB stars,leveraging its unprecedented UV sensitivity and wide-feld survey capabilities.We employed synthetic spectral libraries of M0–M8 type giants for primary stars and the ATLAS 9 atmospheric model grid for companion stars spanning a temperature range of 6500 to 12,000 K.By convolving these model spectra with the CSST multi-band flter system,we computed color–color diagrams(g–y versus NUV–u)to construct a diagnostic grid.This grid incorporates interstellar extinction corrections and establishes a framework for identifying AGB binary candidates through direct comparison between observed photometry and theoretical predictions.Furthermore,we discuss the physical origins of UV excess in AGB stars.This study pioneers a diagnostic framework leveraging CSST’s unique multi-band UV-visible synergy to construct color–color grids for binary candidate identifcation,overcoming limitations of non-simultaneous multi-instrument observations.
基金support from the National Research Foundation(NRF)of South Africasupported by the Ministry of Science and Higher Education of Russia,topic No.FEUZ-2023-0019。
文摘We present the results of our study of the long-period eclipsing binary star V454 Aur.The results are based on spectroscopic data obtained with the UFESéchelle spectrograph and photometric observations from Transiting Exoplanet Survey Satellite(TESS).The derived radial velocity curve is based on 17 spectra obtained between 2021and 2023,covering all orbital phases of this binary system.The orbital period determined from TESS data,P=27.019803±0.000003 days,agrees within uncertainties with the period established in previous studies.The model constructed for the TESS photometric light curve achieves a precision of 0.01%.The effective temperatures of both components,as well as the system metallicity,were directly derived from the spectra and are Teff,A=6250±50 K,Teff,B=5855±50 K,and[Fe/H]=-0.10±0.08,respectively.Our analysis of the photometric and spectroscopic data allowed us to directly compute the luminosities of the components,LA=1.82 L☉and LB=1.07 L☉,their radii,RA=1.15 R☉and RB=1.00 R☉,and their masses,MA=1.137 M☉and MB=1.023 M☉,with uncertainties below 1%.Comparison with evolutionary tracks indicates that the system’s age is 1.18±0.10 Gyr,and both components are still on the main sequence.The V454 Aur system is particularly interesting due to the partial eclipse of the primary component,which results in the“inversion”of the primary and secondary minima in the photometric light curve.
文摘With the advancement of astronomical observation technology,people have a deeper understanding of the formation and evolution of galaxies,but many details of our own Milky Way and other external galaxies are still unknown.Therefore,by studying the formation and orbital transformation mechanism of satellites,planets and stars,the author puts forward a new theory on the formation and evolution of stars and galaxies,thus revealing the hierarchical structure of galaxies and the formation and evolution laws of main sequence stars,red giants,white dwarfs,black dwarfs,supernovae,neutron stars,black holes and quasars.Some special phenomena in the course of star formation and evolution,such as sunspots,flares,fast radio bursts and gamma-ray bursts,have also been revealed.
基金supported by the National Natural Science Foundation of China(Nos.11988101,U1931101,42364001 and 11933008)the Foundation of Education Bureau of Guizhou Province,China(No.KY(2020)003)+1 种基金the Guizhou Provincial Science and Technology Foundation(No.ZK[2022]322)the Guizhou Normal University 2019Special project of training new academics。
文摘In this paper,new light curve fitting and orbital period change analysis of two contact binaries NSVS 9023048 and NSVS 2461789 are presented.We found that both of them are totally eclipsing contact binaries.Our photometric solutions suggest that NSVS 9023048 is a deep contact binary(q=10.14,f=69.2%),however,NSVS 2461789is a shallow one(f=24.4%,q=3.08).The asymmetric light curves of NSVS 2461789 and NSVS 9023048 can be explained by the star-spot activity.At the same time,using the available eclipse times,we first studied the orbital period changes of these two targets.It is discovered that the period of NSVS 9023048 is decreasing at a rate of dP/dt=-1.17×10^(-6)day yr^(-1),which can be explained by mass transfer from the more massive star to the less massive one or angular momentum loss.In addition,the O-C diagrams of NSVS 9023048 and NSVS 2461789show possible cyclic oscillations with a period of 7.29 yr and 9.91 yr,respectively.The cyclic oscillations may be caused by the light-travel time effect due to the presence of a third component.The mass of the tertiary companion is determined to be M_(3)sin(i_(3))=9.05 Mefor NSVS 9023048 and M_(3)sin(i_(3))=0.11 Mefor NSVS 2461789.Based on our calculations,the third body of NSVS 9023048 may be a black hole candidate.Our study also reveals that NSVS 9023048 is stable now.
基金Funding for TESS is provided by the NASA Science Mission Directorate。
文摘In this study,the apsidal motion analyses of the eclipsing binary systems V398 Lac,V2544 Cyg,and V785 Cas are presented.The(O-C)diagrams of the selected systems were constructed using all available and reliable times of minimum light compiled from the literature.As a result,the apsidal motion periods were determined to be 353±50 yr,43.3±5.1 yr and 83.4±8.5 yr,respectively.Furthermore,the TESS light curves of the three systems were analyzed to derive their photometric and absolute parameters.The component masses were determined as follows:for V398 Lac,M_(1)=3.83±0.35 M_(⊙)and M2=3.27±0.35 M_(⊙);for V2544 Cyg,M_(1)=1.75±0.38 M_(⊙)and M2=1.40±0.38 M_(⊙);for V785 Cas,M_(1)=5.64±0.41 M_(⊙)and M2=5.18±0.41 M_(⊙).The parameters related to apsidal motion,as well as the observational and theoretical internal structure constants(K_(2,obs) and K_(2,teo))were calculated for studied binaries.The relativistic contribution to the observed apsidal motion rate was found to be relatively small,constituting less than approximately 5%of the total rate in each system.The theoretical internal structure constants were derived from the evolutionary models,assuming a standard chemical composition of(X,Z)=(0.70,0.01).
基金supported by the National Natural Science Foundation of China(12273008,12025303,12403046)the National SKA Program of China(2022SKA0130104)+3 种基金the Natural Science and Technology Foundation of Guizhou Province(QiankehejichuMS[2025]266,[2023]024,ZK[2022]304)the Foundation of Guizhou Provincial Education Department(KY(2020)003)the Academic New Seedling Fund Project of Guizhou Normal University([2022]B18)the Major Science and Technology Program of Xinjiang Uygur Autonomous Region(2022A03013-4).
文摘The emission of anomalous X-ray pulsars(AXPs)and soft gamma-ray repeaters(SGRs)is believed to be powered by the dissipation of their strong magnetic fields,which coined the name“magnetar”.By combining timing and energy observational results,the magnetar model can be easily appreciated.From a timing perspective,the magnetic field strengths of AXPs and SGRs,which are calculated under the assumption of dipole radiation,are extremely strong.From an energy perspective,the X-ray/soft gamma-ray luminosities of AXPs and SGRs are larger than their rotational energy loss rates(i.e.,L_(x>E_(rot)).It is thus reasonable to assume that the high-energy radiation comes from magnetic energy decay,and the magnetar model has been extensively discussed(or accepted).However,we argue that:(ⅰ)Calculating magnetic fields by assuming that rotational energy loss is dominated by dipole radiation(i.e.,E_(rot)■E_(μ))may be controversial,and we suggest that the energies carried by outflowing particles should also be considered.(ⅱ)The fact that X-ray luminosity is greater than the rotational energy loss rate does not necessarily mean that the emission energy comes from the magnetic field decaying,which requires further observational testing.Furthermore,some observational facts conflict with the“magnetar”model,such as observations of anti-magnetars,high magnetic field pulsars,and radio and X-ray observations of AXPs/SGRs.Therefore,we propose a crusted strange star model as an alternative,which can explain many more observational facts of AXPs/SGRs.
文摘We present a theoretical model for detecting axions from neutron stars in a QCD phase of quark matter. The axions would be produced from a quark-antiquark pair uu¯or dd¯, in loop(s) involving gluons. The chiral anomaly of QCD and the spontaneously broken symmetry are invoked to explain the non-conservation of the axion current. From the coupling form factors, the axion emissivities ϵacan be derived, from which fluxes can be determined. We predict a photon flux, which may be detectable by Fermi LAT, and limits on the QCD mass ma. In this model, axions decay to gamma rays in a 2-photon vertex. We may determine the expected fluxes from the theoretical emissivity. The sensitivity curve from the Fermi Large Area Telescope (Fermi LAT) would allow axion mass constraints for neutron stars as low as ma≤10−14eV 95% C.L. Axions could thus be detectable in gamma rays for neutron stars as distant as 100 kpc. A signal from LIGO GWS 170817 could be placed from the NS-NS merger, which gives an upper limit of ma≤10−10eV.
基金A grant from the Pazy Foundation supported this research.
文摘With a one-dimensional stellar evolution model,we find that massive main sequence stars can accrete mass at very high mass accretion rates without expanding much if they lose a significant fraction of this mass from their outer layers simultaneously with mass accretion.We assume the accretion process is via an accretion disk that launches powerful jets from its inner zones.These jets remove the outer high-entropy layers of the mass-accreting star.This process operates in a negative feedback cycle,as the jets remove more envelope mass when the star expands.With the one-dimensional model,we mimic the mass removal by jets by alternating mass addition and mass removal phases.For the simulated models of 30M☉and 60M☉,the star does not expand much if we remove more than about half of the added mass in not-too-short episodes.This holds even if we deposit the energy the jets do not carry into the envelope.As the star does not expand much,its gravitational potential well stays deep,and the jets are energetic.These results are relevant to bright transient events of binary systems powered by accretion and the launching of jets,e.g.,intermediate luminosity optical transients,including some luminous red novae,the grazing envelope evolution,and the 1837–1856 Great Eruption of Eta Carinae.
文摘The best way to check the validity of our theories(models)is by direct comparison with the experiment(observations).However,this process suffers from numerical inaccuracies,which are not frequently studied and often remain mostly unknown.In this study,we focus on addressing the numerical inaccuracies intrinsic to the process of comparing theory and observations.To achieve this goal,we built four-dimensional(4D)spectral grids for Wolf–Rayet stars(WC and WN spectral classes)and blue supergiants characterized by low metallicity similar to that of the Small Magellanic Cloud.In contrast to lighter(three-dimensional)grids,which rely on a priori assumptions about certain stellar parameters(e.g.,wind velocity)and thus have limited applicability,our 4D grids vary four independent parameters,enabling more flexible and broadly applicable spectral fitting.Utilizing these 4D grids,we developed and validated a fitting approach facilitating direct fits to observed spectra.Through rigorous testing on designated“test”models,we demonstrated that the numerical precision of derived essential stellar parameters,including effective temperature,mass-loss rate,luminosity,and wind velocity,is better than 0.05 dex.Furthermore,we explored the influence of unaccounted factors,including variations in the metal abundances,wind acceleration laws,and clumping,on the precision of the derived parameters.The results indicate that the first two factors have the strongest influence on the numerical accuracy of the derived stellar parameters.Variations in abundances predominantly influenced the mass-loss rate for weak-wind scenarios,while effective temperature and luminosity remained robust.We found that the wind acceleration law influences the numerical uncertainty of the derived wind parameters mostly for models with weak winds.Interestingly,different degrees of clumping demonstrated good precision for spectra with strong winds,contrasting with a decrease in the precision for weak-wind cases.We found also that the accuracy of our approach depends on spectral range and the inclusion of ultraviolet spectral range improves the precision of derived parameters,especially for an object with weak winds.
文摘Stars can form and evolve within gaseous disks around active galactic nuclei(AGNs).In the sub-parsec region of disks around~10~8M_(☉)black holes,stars accrete rapidly,reaching■200 M_(☉)and settling into a quasi-steady state in which accretion balances wind-driven mass loss.Within this environment,their ultimate fate depends critically on the radiative-zone diffusion coefficient(Dmix),which encapsulates various mixing processes and governs chemical transport between surface and core.Using the MESA stellar evolution code,we simulate AGN stars across a range of mixing efficiencies.We find a critical threshold floor value D_(mix,min)≈1010 cm~2 s^(-1)that separates two distinct fates:1."Immortal stars"—when mixing is over-efficient(D_(mix,min)■10^(10)cm~2 s^(-1)),rapid hydrogen replenishment sustains core hydrogen burning,maintains main-sequence equilibrium,rendering the star effectively“immortal.”2."Metamorphic stars"—when mixing is merely efficient(D_(mix,min)<1010 cm~2 s^(-1)),stars exhaust core hydrogen,evolve off-main-sequence,shed mass to≈15 M_(☉),and produce super-solar a-abundances consistent with AGN observations.We conclude that maintaining a mixing floor below this threshold is sufficient to avoid immortality,as flux-induced extra mixing can be effectively modeled via constant floor values.Our estimates provide a foundation for future work on disk enrichment and stellar evolution.
基金partially supported by the National Natural Science Foundation of China 12173034 and 12322304he National Natural Science Foundation of Yunnan Province202301AV070002+1 种基金the Xingdian talent support program of Yunnan Provincethe science research grants from the China Manned Space Project with NO.CMS-CSST-2021-A09,CMS-CSST-2021-A08 and CMS-CSST-2021-B03。
文摘Accurate determinations of metallicity for large,complete stellar samples are essential for advancing various studies of the Milky Way.In this paper,we present a data-driven algorithm that leverages photometric data from the KiDS and the VIKING surveys to estimate stellar absolute magnitudes,effective temperatures,and metallicities.The algorithm is trained and validated using spectroscopic data from LAMOST,SEGUE,APOGEE,and GALAH,as well as a catalog of very metal-poor stars from the literature,and Gaia EDR3 data.This approach enables us to estimate metallicities,effective temperatures,and g-band absolute magnitudes for approximately 0.8 million stars in the KiDS data set.The photometric metallicity estimates exhibit an uncertainty of around 0.28 dex when compared to spectroscopic studies,within the metallicity range of−2 dex to 0.5 dex.The photometric effective temperature estimates have an uncertainty of around 149 K,while the uncertainty in the absolute magnitudes is approximately 0.36 mag.The metallicity estimates are reliable for values down to about−2 dex.This catalog represents a valuable resource for studying the structure and chemical properties of the Milky Way,offering an extensive data set for future investigations into Galactic formation and evolution.
基金the National Natural Science Foundation of China under grant Nos.U2031204,12163005,12373038,12288102,and 12263006the science research grant from the China Manned Space Project with No.CMSCSST-2021-A10+1 种基金the Natural Science Foundation of Xinjiang Nos.2022D01D85 and 2022TSYCLJ0006the Major Science and Technology Program of Xinjiang Uygur Autonomous Region under grant No.2022A03013-3.
文摘The subsurface convective zones (CZs) of massive stars significantly influence many of their key characteristics.Previous studies have paid little attention to the impact of rotation on the subsurface CZ,so we aim to investigate the evolution of this zone in rapidly rotating massive stars.We use the Modules for Experiments in Stellar Astrophysics to simulate the subsurface CZs of massive stars during the main sequence phase.We establish stellar models with initial masses ranging from 5 M⊙to 120 M⊙,incorporating four metallicities (Z=0.02,0.006,0.002,and 0.0001) and three rotational velocities (ω/ωcrit=0,ω/ωcrit=0.50,andω/ωcrit=0.75).We find that rapid rotation leads to an expansion of the subsurface CZ,increases convective velocities,and promotes the development of this zone.Additionally,subsurface CZs can also emerge in stars with lower metallicities.Comparing our models with observations of massive stars in the Galaxy,the Large Magellanic Cloud,and the Small Magellanic Cloud,we find that rotating models better encompass the observed samples.Rotation significantly influences the evolution of the subsurface CZ in massive stars.By comparing with the observed microturbulence on the surfaces of OB stars,we propose that the subsurface CZs may be one of the sources of microturbulence.
基金partially supported by the National Natural Science Foundation of China(NSFC,Grant Nos.12173034 and 12322304)the National Natural Science Foundation of Yunnan Province 202301AV070002+1 种基金the Xingdian talent support program of Yunnan Provincethe science research grants from the China Manned Space Project with No.CMS-CSST-2021-A09,CMS-CSST-2021-A08 and CMS-CSST-2021-B03。
文摘Red clump(RC)stars are reliable standard candles for studying the structure and evolution of the Milky Way.In this study,we present empirical calibrations of RC absolute magnitudes in the Mephisto(v,g,r,i)and CSST(g,r,i)photometric systems using a high-purity sample of 25,059 RC stars cross-matched between APOGEE and Gaia DR3 XP spectra.Through synthetic photometry and polynomial fitting,we find that RC absolute magnitudes exhibit strong dependencies on effective temperature and metallicity,with the strongest variations observed in bluer bands and progressively decreasing towards redder wavelengths.In particular,the Mephisto v band exhibits the highest sensitivity,with variations reaching up to 2.0 mag across the metallicity range(−1.0 dex<[Fe/H]<0.5 dex)and the temperature range(4500–5200 K).The calibrations achieve high precision for all bands,enabling accurate determination of RC absolute magnitudes and distances.Furthermore,we evaluate the metallicity estimation capabilities of both systems using a Random Forest-based method,achieving a precision of 0.12 dex for Mephisto and 0.14 dex for CSST under typical photometric uncertainties(≤0.01 mag).These results provide robust tools for distance and metallicity determinations,supporting future Galactic structure studies with Mephisto and CSST data.
基金supported by the National Natural Science Foundation of China (grant No.12373108)。
文摘The study of carbon-enhanced metal-poor (CEMP) stars is of great significance for understanding the chemical evolution of the early universe and stellar formation.CEMP stars are characterized by carbon overabundance and are classified into several subclasses based on the abundance patterns of neutron-capture elements,including CEMP-s,CEMP-no,CEMP-r,and CEMP-r/s.These subclasses provide important insights into the formation of thefirst stars,early stellar nucleosynthesis,and supernova explosions.However,one of the major challenges in CEMP star research is the relatively small sample size of identified stars,which limits statistical analyses and hinders a comprehensive understanding of their properties.Fortunately,a series of large-scale spectroscopic survey projects have been launched and developed in recent years,providing unprecedented opportunities and technical challenges for the search and study of CEMP stars.To this end,this paper draws on the progress and future prospects of existing methods in constructing large CEMP data sets and offers an in-depth discussion from a technical standpoint,focusing on the strengths and limitations.In addition,we review recent advancements in the identification of CEMP stars,emphasizing the growing role of machine learning in processing and analyzing the increasingly large data sets generated by modern astronomical surveys.Compared to traditional spectral analysis methods,machine learning offers greater efficiency in handling complex data,automatic extraction of stellar parameters,and improved prediction accuracy.Despite these advancements,the research faces persistent challenges,including the scarcity of labeled samples,limitations imposed by low-resolution spectra,and the lack of interpretability in machine learning models.To address these issues,the paper proposes potential solutions and future research directions aimed at advancing the study of CEMP stars and enhancing our understanding of their role in the chemical evolution of the universe.
文摘In the present article,we introduce a completely new regular model for static,spherically symmetric celestial fluid spheres in embedding classⅠspacetime.In this regard,needfully,we propose a new suitable metric potential e^(λ(r))to generate the present model.The various analyses on energy density,pressure,anisotropic factor,mass,compactness parameter,redshift,and energy condition make sure the model is physically viable on the ground of model stars Vela X-1,Cen X-3,SMC X-4,and LMC X-4.The reported solutions also respect the equilibrium state by satisfying the Tolman-Oppenheimer-Volkoff(TOV)equation and ensure stability by satisfying the causality condition,condition on the adiabatic index,and Harrison-Zeldovich-Novikov condition.The generated M-R graph matches the ranges of masses and radii for the model compact stars.Additionally,this study provides estimates of the moment of inertia based on the I-M graph.
基金supported by the National Natural Science Foundation of China(NSFC)through grants 12173047,12373035,12322306,12373028,12233009 and 12133002X.C.and S.W.acknowledge supports from the Youth Innovation Promotion Association of the Chinese Academy of Sciences(CAS,Nos.2022055 and 2023065)+2 种基金support from the National Key Research and Development Program of China,grant 2022YFF0503404Funding for the DPAC has been provided by national institutions,in particular the institutions participating in the Gaia Multilateral AgreementFunding for the project has been provided by the National Development and Reform Commission。
文摘δScuti(δSct)stars are potential distance tracers for studying the Milky Way structure.We conduct a comprehensive analysis of the period-luminosity(PL)and period-luminosity-metallicity(PLZ)relations forδSct stars,integrating data from the Zwicky Transient Facility,the Transiting Exoplanet Survey Satellite,Large Sky Area Multi-Object Fiber Spectroscopic Telescope,Apache Point Observatory Galactic Evolution Experiment,and Gaia.To mitigate the impact of the Gaia parallax zero point offset,we applied a correction method,determining the optimal zero point value to be zp(?)=35±2μas.Using the three best bands,by varying the parallax error threshold,we found that the total error of the PLR zero point was minimized to 0.9%at a parallax error threshold of 6%.With this threshold,we derived the PL and PLZ relations for nine bands(from optical to mid-infrared)and five Wesenheit bands.Through our analysis,we conclude that the influence of metallicity on the PLR ofδSct stars is not significant,and the differences across various bands are minimal.
