Shi-Jie Gao, Yi-Xuan Shao, Pei Wang, Ping Zhou, Xiang-Dong Li, Lei Zhang, Joseph W. Kania, Duncan R. Lorimer, Di Li
Observations show that globular clusters might be among the best places to find millisecond pulsars. However, the globular cluster Terzan 6 seems to be an exception without any pulsar discovered, although its high stellar encounter rate suggests that it harbors dozens of them. We report the discovery of the first radio pulsar, PSR J1751-3116A, likely associated with Terzan 6 in a search of C-band (4-8 GHz) data from the Green Bank Telescope with a spin period of 5.33 ms and dispersion measure, DM$simeq$383 ${rm pc~cm^{-3}}$. The mean flux density of this pulsar is approximately 3 ${rm mu Jy}$. The DM agrees well with predictions from the Galactic free electron density model, assuming a distance of 6.7 kpc for Terzan 6. PSR J1751-3116A is likely an isolated millisecond pulsar, potentially formed through dynamical interactions, considering the core-collapsed classification and the exceptionally high stellar encounter rate of Terzan 6. This is the highest radio frequency observation that has led to the discovery of a pulsar in a globular cluster to date. While L-band (1-2 GHz) observations of this cluster are unlikely to yield significant returns due to propagation effects, we predict that further pulsar discoveries in Terzan 6 will be made by existing radio telescopes at higher frequencies.
观测结果表明，球状星团可能是发现毫秒脉冲星的最佳地点之一。然而，球状星团 Terzan 6 似乎是个例外，没有发现任何脉冲星，尽管它的高恒星遭遇率表明它蕴藏着数十颗脉冲星。我们报告了对绿岸望远镜C波段（4-8 GHz）数据的搜索结果，发现了第一颗射电脉冲星PSR J1751-3116A，它可能与泰尔赞6号有关，自旋周期为5.33毫秒，色散测量值为DM$simeq$383 ${rm pc~^cm{-3}}$。这颗脉冲星的主题通量密度大约为 3 ${rm mu Jy}$。DM与银河系自由电子密度模型的预测值非常吻合，假设泰山6号的距离为6.7 kpc。PSR J1751-3116A很可能是一颗孤立的毫秒脉冲星，有可能是通过动力学相互作用形成的，考虑到泰尔赞6号的核心塌缩分类和极高的恒星相遇率。这是迄今为止发现球状星团中脉冲星的最高射电频率观测。虽然由于传播效应，对该星团的 L 波段（1-2 GHz）观测不太可能产生显著的回报，但我们预测现有的射电望远镜将在更高频率上进一步发现 Terzan 6 中的脉冲星。
{"title":"Discovery of a millisecond pulsar associated with Terzan 6","authors":"Shi-Jie Gao, Yi-Xuan Shao, Pei Wang, Ping Zhou, Xiang-Dong Li, Lei Zhang, Joseph W. Kania, Duncan R. Lorimer, Di Li","doi":"arxiv-2409.10801","DOIUrl":"https://doi.org/arxiv-2409.10801","url":null,"abstract":"Observations show that globular clusters might be among the best places to\u0000find millisecond pulsars. However, the globular cluster Terzan 6 seems to be an\u0000exception without any pulsar discovered, although its high stellar encounter\u0000rate suggests that it harbors dozens of them. We report the discovery of the\u0000first radio pulsar, PSR J1751-3116A, likely associated with Terzan 6 in a\u0000search of C-band (4-8 GHz) data from the Green Bank Telescope with a spin\u0000period of 5.33 ms and dispersion measure, DM$simeq$383 ${rm pc~cm^{-3}}$. The\u0000mean flux density of this pulsar is approximately 3 ${rm mu Jy}$. The DM\u0000agrees well with predictions from the Galactic free electron density model,\u0000assuming a distance of 6.7 kpc for Terzan 6. PSR J1751-3116A is likely an\u0000isolated millisecond pulsar, potentially formed through dynamical interactions,\u0000considering the core-collapsed classification and the exceptionally high\u0000stellar encounter rate of Terzan 6. This is the highest radio frequency\u0000observation that has led to the discovery of a pulsar in a globular cluster to\u0000date. While L-band (1-2 GHz) observations of this cluster are unlikely to yield\u0000significant returns due to propagation effects, we predict that further pulsar\u0000discoveries in Terzan 6 will be made by existing radio telescopes at higher\u0000frequencies.","PeriodicalId":501068,"journal":{"name":"arXiv - PHYS - Solar and Stellar Astrophysics","volume":"34 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142269217","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Adolfo S. Carvalho, Gregory J. Herczeg, Kevin France, Lynne A. Hillenbrand
The eruptive YSO FU Ori is the eponym of its variable class. FU Ori stars are known to undergo outbursts with amplitudes of $>4$ magnitudes in the $V$ band and durations of several decades. Interaction with a binary companion is one proposed outburst trigger, so understanding both components of the FU Ori system is crucial. A recent HST/STIS observation of the FU Ori system clearly resolves its North and South components. We report here on the spectrum of FU Ori South. We detect NUV continuum emission but no FUV continuum, although several bright emission lines consistent with those seen in T Tauri stars are present. The presence of the C II] 2325 multiplet and many H$_2$ lines indicate active accretion. We estimate the extinction to the source and find that the UV spectrum favors $A_V < 4$, contrary to past estimates based on the NIR spectrum.
爆发性 YSO FU Ori 是其变星类的同名。据了解，FU Ori恒星会发生爆发，在V$波段的振幅>4$等，持续时间长达数十年。与双星伴星的相互作用是触发爆发的原因之一，因此了解 FU Ori 星系统的两个组成部分至关重要。最近HST/STIS对FU Ori系统的观测清楚地分辨出了它的南北两个部分。我们在此报告 FUOri 南部的光谱。我们探测到了近紫外连续发射，但没有发现远紫外连续发射，不过有几条明亮的发射线，与金牛座恒星中出现的发射线一致。C II] 2325 多倍线和许多 H$_2$ 线的存在表明存在活跃的吸积现象。我们估算了该星源的消光，发现紫外光谱倾向于$A_V < 4$，这与过去基于近红外光谱的估算相反。
{"title":"The FUV Spectrum of FU Ori South","authors":"Adolfo S. Carvalho, Gregory J. Herczeg, Kevin France, Lynne A. Hillenbrand","doi":"arxiv-2409.10796","DOIUrl":"https://doi.org/arxiv-2409.10796","url":null,"abstract":"The eruptive YSO FU Ori is the eponym of its variable class. FU Ori stars are\u0000known to undergo outbursts with amplitudes of $>4$ magnitudes in the $V$ band\u0000and durations of several decades. Interaction with a binary companion is one\u0000proposed outburst trigger, so understanding both components of the FU Ori\u0000system is crucial. A recent HST/STIS observation of the FU Ori system clearly\u0000resolves its North and South components. We report here on the spectrum of FU\u0000Ori South. We detect NUV continuum emission but no FUV continuum, although\u0000several bright emission lines consistent with those seen in T Tauri stars are\u0000present. The presence of the C II] 2325 multiplet and many H$_2$ lines indicate\u0000active accretion. We estimate the extinction to the source and find that the UV\u0000spectrum favors $A_V < 4$, contrary to past estimates based on the NIR\u0000spectrum.","PeriodicalId":501068,"journal":{"name":"arXiv - PHYS - Solar and Stellar Astrophysics","volume":"17 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142257979","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Francisco C. De Gerónimo, Marcelo M. Miller Bertolami, Tiara Battich, Xiaodong Tang, Márcio Catelan, Alejandro H. Córsico, Yunjun Li, Xiao Fang, Leandro G. Althaus
Recent determinations of the total rate of the 12C+12C nuclear reaction show non-negligible differences with the reference reaction rate commonly used in previous stellar simulations. In addition, the current uncertainties in determining each exit channel constitute one of the main uncertainties in shaping the inner structure of super asymptotic giant branch stars that could have a measurable impact on the properties of pulsating ultra-massive white dwarfs (WDs). We explore how new determinations of the nuclear reaction rate and its branching ratios affect the evolution of WD progenitors. We show that the current uncertainties in the branching ratios constitute the main uncertainty factor in determining the inner composition of ultra-massive WDs and their progenitors. We found that the use of extreme branching ratios leads to differences in the central abundances of 20Ne of at most 17%, which are translated into differences of at most 1.3 and 0.8% in the cooling times and size of the crystallized core. However, the impact on the pulsation properties is small, less than 1 s for the asymptotic period spacing. We found that the carbon burns partially in the interior of ultra-massive WD progenitors within a particular range of masses, leaving a hybrid CONe-core composition in their cores. The evolution of these new kinds of predicted objects differs substantially from the evolution of objects with pure CO cores. Differences in the size of the crystallized core and cooling times of up to 15 and 6%, respectively leading to distinct patterns in the period spacing distribution.
{"title":"Impact of current uncertainties in the 12C+12C nuclear reaction rate on intermediate-mass stars and massive white dwarfs","authors":"Francisco C. De Gerónimo, Marcelo M. Miller Bertolami, Tiara Battich, Xiaodong Tang, Márcio Catelan, Alejandro H. Córsico, Yunjun Li, Xiao Fang, Leandro G. Althaus","doi":"arxiv-2409.10793","DOIUrl":"https://doi.org/arxiv-2409.10793","url":null,"abstract":"Recent determinations of the total rate of the 12C+12C nuclear reaction show\u0000non-negligible differences with the reference reaction rate commonly used in\u0000previous stellar simulations. In addition, the current uncertainties in\u0000determining each exit channel constitute one of the main uncertainties in\u0000shaping the inner structure of super asymptotic giant branch stars that could\u0000have a measurable impact on the properties of pulsating ultra-massive white\u0000dwarfs (WDs). We explore how new determinations of the nuclear reaction rate\u0000and its branching ratios affect the evolution of WD progenitors. We show that\u0000the current uncertainties in the branching ratios constitute the main\u0000uncertainty factor in determining the inner composition of ultra-massive WDs\u0000and their progenitors. We found that the use of extreme branching ratios leads\u0000to differences in the central abundances of 20Ne of at most 17%, which are\u0000translated into differences of at most 1.3 and 0.8% in the cooling times and\u0000size of the crystallized core. However, the impact on the pulsation properties\u0000is small, less than 1 s for the asymptotic period spacing. We found that the\u0000carbon burns partially in the interior of ultra-massive WD progenitors within a\u0000particular range of masses, leaving a hybrid CONe-core composition in their\u0000cores. The evolution of these new kinds of predicted objects differs\u0000substantially from the evolution of objects with pure CO cores. Differences in\u0000the size of the crystallized core and cooling times of up to 15 and 6%,\u0000respectively leading to distinct patterns in the period spacing distribution.","PeriodicalId":501068,"journal":{"name":"arXiv - PHYS - Solar and Stellar Astrophysics","volume":"6 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142269175","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Paola Marigo, Francesco Addari, Diego Bossini, Alessandro Bressan, Guglielmo Costa, Leo Girardi, Michele Trabucchi, Guglielmo Volpato
We address the critical need for accurate Rosseland mean gas opacities in high-pressure environments, spanning temperatures from 100 K to 32000 K. Current opacity tables from Wichita State University and AESOPUS 2.0 are limited to $log(R) le 1$, where $R=rho, T_6^{-3}$ in units of $mathrm{g},mathrm{cm}^{-3}(10^6mathrm{K})^{-3}$. This is insufficient for modeling very low-mass stars, brown dwarfs, and planets with atmospheres exhibiting higher densities and pressures ($log(R) > 1$). Leveraging extensive databases such as ExoMol, ExoMolOP, MoLLIST, and HITEMP, we focus on expanding the AESOPUS opacity calculations to cover a broad range of pressure and density conditions ($-8 leq log(R) leq +6$). We incorporate the thermal Doppler mechanism and micro-turbulence velocity. Pressure broadening effects on molecular transitions, leading to Lorentzian or Voigt profiles, are explored in the context of atmospheric profiles for exoplanets, brown dwarfs, and low-mass stars. We also delve into the impact of electron degeneracy and non-ideal effects such as ionization potential depression under high-density conditions, emphasizing its notable influence on Rosseland mean opacities at temperatures exceeding $10,000$ K. As a result, this study expands AESOPUS public web interface for customized gas chemical mixtures, promoting flexibility in opacity calculations based on specific research needs. Additionally, pre-computed opacity tables, inclusive of condensates, are provided. We present a preliminary application to evolutionary models for very low-mass stars.
{"title":"AESOPUS 2.1: Low-Temperature Opacities Extended to High Pressure","authors":"Paola Marigo, Francesco Addari, Diego Bossini, Alessandro Bressan, Guglielmo Costa, Leo Girardi, Michele Trabucchi, Guglielmo Volpato","doi":"arxiv-2409.10905","DOIUrl":"https://doi.org/arxiv-2409.10905","url":null,"abstract":"We address the critical need for accurate Rosseland mean gas opacities in\u0000high-pressure environments, spanning temperatures from 100 K to 32000 K.\u0000Current opacity tables from Wichita State University and AESOPUS 2.0 are\u0000limited to $log(R) le 1$, where $R=rho, T_6^{-3}$ in units of\u0000$mathrm{g},mathrm{cm}^{-3}(10^6mathrm{K})^{-3}$. This is insufficient for\u0000modeling very low-mass stars, brown dwarfs, and planets with atmospheres\u0000exhibiting higher densities and pressures ($log(R) > 1$). Leveraging extensive\u0000databases such as ExoMol, ExoMolOP, MoLLIST, and HITEMP, we focus on expanding\u0000the AESOPUS opacity calculations to cover a broad range of pressure and density\u0000conditions ($-8 leq log(R) leq +6$). We incorporate the thermal Doppler\u0000mechanism and micro-turbulence velocity. Pressure broadening effects on\u0000molecular transitions, leading to Lorentzian or Voigt profiles, are explored in\u0000the context of atmospheric profiles for exoplanets, brown dwarfs, and low-mass\u0000stars. We also delve into the impact of electron degeneracy and non-ideal\u0000effects such as ionization potential depression under high-density conditions,\u0000emphasizing its notable influence on Rosseland mean opacities at temperatures\u0000exceeding $10,000$ K. As a result, this study expands AESOPUS public web\u0000interface for customized gas chemical mixtures, promoting flexibility in\u0000opacity calculations based on specific research needs. Additionally,\u0000pre-computed opacity tables, inclusive of condensates, are provided. We present\u0000a preliminary application to evolutionary models for very low-mass stars.","PeriodicalId":501068,"journal":{"name":"arXiv - PHYS - Solar and Stellar Astrophysics","volume":"194 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142257981","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Stars play a key role in the evolution of the Universe, as sources of radiation, as dynamical engines, and as chemical factories. Outputs of stellar models are then central to various studies in astrophysics. Stellar physics links fundamental physical aspects to hydrodynamic and magnetohydrodynamic processes, and the validity of stellar models depends directly on the modelling of these complex mechanisms. We describe here the different transport processes at work in stellar interiors and how the modelling of these processes can be improved thanks to the unique ability of asteroseismology, the study of stellar oscillations, to probe the internal structure and dynamics of stars.
{"title":"Mixing processes in stars","authors":"P. Eggenberger","doi":"arxiv-2409.11354","DOIUrl":"https://doi.org/arxiv-2409.11354","url":null,"abstract":"Stars play a key role in the evolution of the Universe, as sources of\u0000radiation, as dynamical engines, and as chemical factories. Outputs of stellar\u0000models are then central to various studies in astrophysics. Stellar physics\u0000links fundamental physical aspects to hydrodynamic and magnetohydrodynamic\u0000processes, and the validity of stellar models depends directly on the modelling\u0000of these complex mechanisms. We describe here the different transport processes\u0000at work in stellar interiors and how the modelling of these processes can be\u0000improved thanks to the unique ability of asteroseismology, the study of stellar\u0000oscillations, to probe the internal structure and dynamics of stars.","PeriodicalId":501068,"journal":{"name":"arXiv - PHYS - Solar and Stellar Astrophysics","volume":"36 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142269174","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sarah Blunt, Jason Jinfei Wang, Vighnesh Nagpal, Lea Hirsch, Roberto Tejada, Tirth Dharmesh Surti, Sofia Covarrubias, Thea McKenna, Rodrigo Ferrer Chávez, Jorge Llop-Sayson, Mireya Arora, Amanda Chavez, Devin Cody, Saanika Choudhary, Adam Smith, William Balmer, Tomas Stolker, Hannah Gallamore, Clarissa R. Do Ó, Eric L. Nielsen, Robert J. De Rosa
orbitize! is a package for Bayesian modeling of the orbital parameters of resolved binary objects from time series measurements. It was developed with the needs of the high-contrast imaging community in mind, and has since also become widely used in the binary star community. A generic orbitize! use case involves translating relative astrometric time series, optionally combined with radial velocity or astrometric time series, into a set of derived orbital posteriors. This paper is published alongside the release of orbitize! version 3.0, which has seen significant enhancements in functionality and accessibility since the release of version 1.0 (Blunt et al., 2020).
{"title":"orbitize! v3: Orbit fitting for the High-contrast Imaging Community","authors":"Sarah Blunt, Jason Jinfei Wang, Vighnesh Nagpal, Lea Hirsch, Roberto Tejada, Tirth Dharmesh Surti, Sofia Covarrubias, Thea McKenna, Rodrigo Ferrer Chávez, Jorge Llop-Sayson, Mireya Arora, Amanda Chavez, Devin Cody, Saanika Choudhary, Adam Smith, William Balmer, Tomas Stolker, Hannah Gallamore, Clarissa R. Do Ó, Eric L. Nielsen, Robert J. De Rosa","doi":"arxiv-2409.11573","DOIUrl":"https://doi.org/arxiv-2409.11573","url":null,"abstract":"orbitize! is a package for Bayesian modeling of the orbital parameters of\u0000resolved binary objects from time series measurements. It was developed with\u0000the needs of the high-contrast imaging community in mind, and has since also\u0000become widely used in the binary star community. A generic orbitize! use case\u0000involves translating relative astrometric time series, optionally combined with\u0000radial velocity or astrometric time series, into a set of derived orbital\u0000posteriors. This paper is published alongside the release of orbitize! version\u00003.0, which has seen significant enhancements in functionality and accessibility\u0000since the release of version 1.0 (Blunt et al., 2020).","PeriodicalId":501068,"journal":{"name":"arXiv - PHYS - Solar and Stellar Astrophysics","volume":"5 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142257937","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Giulia Ricciardi, Sierk E. van Terwisga, Veronica Roccatagliata, Alvaro Hacar, Thomas Henning, Walter Del Pozzo
Aims. The goal of this work is to comprehensively characterize the impact of stellar multiplicity on Class II disks in the L1641 and L1647 regions of Orion A (~1-3 Myr), part of the Survey of Orion Disks with ALMA (SODA). We characterize the protostellar multiplicity using the Atacama Large Millimeter/submillimeter Array (ALMA), the ESO-VISTA, and Hubble Space telescopes. The resulting sample of 65 multiple systems represents the largest catalogue of wide binary systems to date (projected separation >1000 AU), allowing a more robust statistical characterization of the evolution and properties of protoplanetary disks. Methods. The disk population was observed in continuum with ALMA at 225 GHz, with a median rms of 1.5 Mearth. Combining these data (resolution ~1.1arcsec ) with the ESO-VISTA near-infrared survey of the Orion A cloud (resolution ~0.7arcsec ), multiple systems are assembled and selected by an iterative inside-out search in projected separation (>1000 AU). Results. We identify 61 binary systems, 3 triple systems, and one quadruple system. The separation range is between 1000 and 10^4 AU. The dust mass distributions inferred with the Kaplan-Meier estimator yield a median mass of 3.23+0.6-0.4 Mearth for primary disks and 3.88+0.3-0.3 Mearth for secondary disks.
{"title":"Survey of Orion Disks with ALMA (SODA) III: Disks in wide binary systems in L1641 and L1647","authors":"Giulia Ricciardi, Sierk E. van Terwisga, Veronica Roccatagliata, Alvaro Hacar, Thomas Henning, Walter Del Pozzo","doi":"arxiv-2409.11485","DOIUrl":"https://doi.org/arxiv-2409.11485","url":null,"abstract":"Aims. The goal of this work is to comprehensively characterize the impact of\u0000stellar multiplicity on Class II disks in the L1641 and L1647 regions of Orion\u0000A (~1-3 Myr), part of the Survey of Orion Disks with ALMA (SODA). We\u0000characterize the protostellar multiplicity using the Atacama Large\u0000Millimeter/submillimeter Array (ALMA), the ESO-VISTA, and Hubble Space\u0000telescopes. The resulting sample of 65 multiple systems represents the largest\u0000catalogue of wide binary systems to date (projected separation >1000 AU),\u0000allowing a more robust statistical characterization of the evolution and\u0000properties of protoplanetary disks. Methods. The disk population was observed\u0000in continuum with ALMA at 225 GHz, with a median rms of 1.5 Mearth. Combining\u0000these data (resolution ~1.1arcsec ) with the ESO-VISTA near-infrared survey of\u0000the Orion A cloud (resolution ~0.7arcsec ), multiple systems are assembled and\u0000selected by an iterative inside-out search in projected separation (>1000 AU).\u0000Results. We identify 61 binary systems, 3 triple systems, and one quadruple\u0000system. The separation range is between 1000 and 10^4 AU. The dust mass\u0000distributions inferred with the Kaplan-Meier estimator yield a median mass of\u00003.23+0.6-0.4 Mearth for primary disks and 3.88+0.3-0.3 Mearth for secondary\u0000disks.","PeriodicalId":501068,"journal":{"name":"arXiv - PHYS - Solar and Stellar Astrophysics","volume":"77 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142257939","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Morgan MacLeod, Sarah Blunt, Robert J. De Rosa, Andrea K. Dupree, Thomas Granzer, Graham M. Harper, Caroline D. Huang, Emily M. Leiner, Abraham Loeb, Eric L. Nielsen, Klaus G. Strassmeier, Jason J. Wang, Michael Weber
We examine a century of radial velocity, visual magnitude, and astrometric observations of the nearest red supergiant, Betelgeuse, in order to reexamine the century-old assertion that Betelgeuse might be a spectroscopic binary. These data reveal Betelgeuse varying stochastically over years and decades due to its boiling, convective envelope, periodically with a $ 5.78$~yr long secondary period, and quasi-periodically from pulsations with periods of several hundred days. We show that the long secondary period is consistent between astrometric and RV datasets, and argue that it indicates a low-mass companion to Betelgeuse, less than a solar mass, orbiting in a 2,110 day period at a separation of just over twice Betelgeuse's radius. The companion star would be nearly twenty times less massive and a million times fainter than Betelgeuse, with similar effective temperature, effectively hiding it in plain sight near one of the best-studied stars in the night sky. The astrometric data favor an edge-on binary with orbital plane aligned with Betelgeuse's measured spin axis. Tidal spin-orbit interaction drains angular momentum from the orbit and spins up Betelgeuse, explaining the spin--orbit alignment and Betelgeuse's anomalously rapid spin. In the future, the orbit will decay until the companion is swallowed by Betelgeuse in the next 10,000 years.
{"title":"Radial Velocity and Astrometric Evidence for a Close Companion to Betelgeuse","authors":"Morgan MacLeod, Sarah Blunt, Robert J. De Rosa, Andrea K. Dupree, Thomas Granzer, Graham M. Harper, Caroline D. Huang, Emily M. Leiner, Abraham Loeb, Eric L. Nielsen, Klaus G. Strassmeier, Jason J. Wang, Michael Weber","doi":"arxiv-2409.11332","DOIUrl":"https://doi.org/arxiv-2409.11332","url":null,"abstract":"We examine a century of radial velocity, visual magnitude, and astrometric\u0000observations of the nearest red supergiant, Betelgeuse, in order to reexamine\u0000the century-old assertion that Betelgeuse might be a spectroscopic binary.\u0000These data reveal Betelgeuse varying stochastically over years and decades due\u0000to its boiling, convective envelope, periodically with a $ 5.78$~yr long\u0000secondary period, and quasi-periodically from pulsations with periods of\u0000several hundred days. We show that the long secondary period is consistent\u0000between astrometric and RV datasets, and argue that it indicates a low-mass\u0000companion to Betelgeuse, less than a solar mass, orbiting in a 2,110 day period\u0000at a separation of just over twice Betelgeuse's radius. The companion star\u0000would be nearly twenty times less massive and a million times fainter than\u0000Betelgeuse, with similar effective temperature, effectively hiding it in plain\u0000sight near one of the best-studied stars in the night sky. The astrometric data\u0000favor an edge-on binary with orbital plane aligned with Betelgeuse's measured\u0000spin axis. Tidal spin-orbit interaction drains angular momentum from the orbit\u0000and spins up Betelgeuse, explaining the spin--orbit alignment and Betelgeuse's\u0000anomalously rapid spin. In the future, the orbit will decay until the companion\u0000is swallowed by Betelgeuse in the next 10,000 years.","PeriodicalId":501068,"journal":{"name":"arXiv - PHYS - Solar and Stellar Astrophysics","volume":"32 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142257974","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hugo Tranin, Nadejda Blagorodnova, Viraj Karambelkar, Paul J. Groot, Steven Bloemen, Paul M. Vreeswijk, Daniëlle Pieterse, Jan van Roestel
After the main sequence phase, stars more massive than 2.5 M$_odot$ rapidly evolve through the Hertzsprung gap as yellow giants and supergiants (YSG), before settling into the red giant branch. Identifying YSG in nearby galaxies is crucial for pinpointing progenitors of luminous red novae (LRNe) - astrophysical transients attributed to stellar mergers. In the era of extensive transient surveys like the Vera Rubin Observatory's LSST, this approach offers a new way to predict and select common envelope transients. This study investigates potential progenitors and precursors of LRNe by analysing Hubble Space Telescope (HST) photometry of stellar populations in galaxies within 20 Mpc to identify YSG candidates. Additionally, we use ZTF and MeerLICHT/BlackGEM to identify possible precursors, preparing for future observations by the LSST. We compiled a sample of 369 galaxies with HST exposures in the F475W, F555W, F606W, and F814W filters. We identified YSG candidates using MESA stellar evolution tracks and statistical analysis of color-magnitude diagrams (CMDs). Our sample includes 246,573 YSG candidates with masses between 3 and 20 $M_odot$ and is affected by various contaminants, such as foreground stars and extinguished main-sequence stars. After excluding foreground stars using Gaia proper motions, contamination is estimated at 1.7% from foreground stars and 20% from extinction affecting main-sequence stars. Combining our YSG candidates with time-domain catalogs yielded several interesting candidates. Notably, we identified 12 LRN precursor candidates for which followup is encouraged. We highlight the importance of monitoring future transients that match YSG candidates to avoid missing potential LRNe and other rare transients. LSST will be a game changer in the search for LRN progenitors and precursors, discovering over 300,000 new YSG and 100 precursors within 20 Mpc.
{"title":"Hertzsprung gap stars in nearby galaxies and the Quest for Luminous Red Novae Progenitors","authors":"Hugo Tranin, Nadejda Blagorodnova, Viraj Karambelkar, Paul J. Groot, Steven Bloemen, Paul M. Vreeswijk, Daniëlle Pieterse, Jan van Roestel","doi":"arxiv-2409.11347","DOIUrl":"https://doi.org/arxiv-2409.11347","url":null,"abstract":"After the main sequence phase, stars more massive than 2.5 M$_odot$ rapidly\u0000evolve through the Hertzsprung gap as yellow giants and supergiants (YSG),\u0000before settling into the red giant branch. Identifying YSG in nearby galaxies\u0000is crucial for pinpointing progenitors of luminous red novae (LRNe) -\u0000astrophysical transients attributed to stellar mergers. In the era of extensive\u0000transient surveys like the Vera Rubin Observatory's LSST, this approach offers\u0000a new way to predict and select common envelope transients. This study\u0000investigates potential progenitors and precursors of LRNe by analysing Hubble\u0000Space Telescope (HST) photometry of stellar populations in galaxies within 20\u0000Mpc to identify YSG candidates. Additionally, we use ZTF and MeerLICHT/BlackGEM\u0000to identify possible precursors, preparing for future observations by the LSST.\u0000We compiled a sample of 369 galaxies with HST exposures in the F475W, F555W,\u0000F606W, and F814W filters. We identified YSG candidates using MESA stellar\u0000evolution tracks and statistical analysis of color-magnitude diagrams (CMDs).\u0000Our sample includes 246,573 YSG candidates with masses between 3 and 20\u0000$M_odot$ and is affected by various contaminants, such as foreground stars and\u0000extinguished main-sequence stars. After excluding foreground stars using Gaia\u0000proper motions, contamination is estimated at 1.7% from foreground stars and\u000020% from extinction affecting main-sequence stars. Combining our YSG\u0000candidates with time-domain catalogs yielded several interesting candidates.\u0000Notably, we identified 12 LRN precursor candidates for which followup is\u0000encouraged. We highlight the importance of monitoring future transients that\u0000match YSG candidates to avoid missing potential LRNe and other rare transients.\u0000LSST will be a game changer in the search for LRN progenitors and precursors,\u0000discovering over 300,000 new YSG and 100 precursors within 20 Mpc.","PeriodicalId":501068,"journal":{"name":"arXiv - PHYS - Solar and Stellar Astrophysics","volume":"57 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142257940","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Noor AftabAndrew, XunheAndrew, Zhang, David R. Mittelman, Dennis di Cicco, Sean Walker, David H. Sliski, Julia Homa, Colin Holm-Hansen, Mary Putman, David Schiminovich, Arne Henden, Gary Walker
The Mittelman-di Cicco-Walker (MDW) H$alpha$ Sky Survey is an autonomously-operated and ongoing all-sky imaging survey in the narrowband H$alpha$ wavelength. The survey was founded by amateur astronomers, and is presented here in its first stage of refinement for rigorous scientific use. Each field is exposed through an H$alpha$ filter with a 3nm bandwidth for a total of four hours, with a pixel scale of 3.2 arcsec. Here, we introduce the first Data Release of the MDW H$alpha$ Survey (Data Release 0, or DR0), spanning 238 fields in the region of Orion (~3100 deg$^2$). DR0 includes: calibrated mean fields, star-removed mean fields, a point source catalog matched to Data Release 1 of the Panoramic Survey Telescope and Rapid Response System (Pan-STARRS1) and the INT Galactic Plane Survey (IGAPS), and mosaics.
{"title":"The MDW Hα Sky Survey: Data Release 0","authors":"Noor AftabAndrew, XunheAndrew, Zhang, David R. Mittelman, Dennis di Cicco, Sean Walker, David H. Sliski, Julia Homa, Colin Holm-Hansen, Mary Putman, David Schiminovich, Arne Henden, Gary Walker","doi":"arxiv-2409.11481","DOIUrl":"https://doi.org/arxiv-2409.11481","url":null,"abstract":"The Mittelman-di Cicco-Walker (MDW) H$alpha$ Sky Survey is an\u0000autonomously-operated and ongoing all-sky imaging survey in the narrowband\u0000H$alpha$ wavelength. The survey was founded by amateur astronomers, and is\u0000presented here in its first stage of refinement for rigorous scientific use.\u0000Each field is exposed through an H$alpha$ filter with a 3nm bandwidth for a\u0000total of four hours, with a pixel scale of 3.2 arcsec. Here, we introduce the\u0000first Data Release of the MDW H$alpha$ Survey (Data Release 0, or DR0),\u0000spanning 238 fields in the region of Orion (~3100 deg$^2$). DR0 includes:\u0000calibrated mean fields, star-removed mean fields, a point source catalog\u0000matched to Data Release 1 of the Panoramic Survey Telescope and Rapid Response\u0000System (Pan-STARRS1) and the INT Galactic Plane Survey (IGAPS), and mosaics.","PeriodicalId":501068,"journal":{"name":"arXiv - PHYS - Solar and Stellar Astrophysics","volume":"2 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142257938","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：