Pub Date : 2023-05-05DOI: 10.1007/s41116-023-00036-z
Ilya G. Usoskin
Here we review present knowledge of the long-term behaviour of solar activity on a multi-millennial timescale, as reconstructed using the indirect proxy method. The concept of solar activity is discussed along with an overview of the dedicated indices used to quantify different aspects of variable solar activity, with special emphasis on sunspot numbers. Over long timescales, quantitative information about past solar activity is historically obtained using a method based on indirect proxies, such as cosmogenic isotopes (^{14})C and (^{10})Be in natural stratified archives (e.g., tree rings or ice cores). We give a historical overview of the development of the proxy-based method for past solar-activity reconstruction over millennia, as well as a description of the modern state of the art. Special attention is paid to the verification and cross-calibration of reconstructions. It is argued that the method of cosmogenic isotopes makes a solid basis for studies of solar variability in the past on a long timescale (centuries to millennia) during the Holocene (the past (sim )12 millennia). A separate section is devoted to reconstructions of extremely rare solar eruptive events in the past, based on both cosmogenic-proxy data in terrestrial and lunar natural archives, as well as statistics of sun-like stars. Finally, the main features of the long-term evolution of solar magnetic activity, including the statistics of grand minima and maxima occurrence, are summarized and their possible implications, especially for solar/stellar dynamo theory, are discussed.
{"title":"A history of solar activity over millennia","authors":"Ilya G. Usoskin","doi":"10.1007/s41116-023-00036-z","DOIUrl":"10.1007/s41116-023-00036-z","url":null,"abstract":"<div><p>Here we review present knowledge of the long-term behaviour of solar activity on a multi-millennial timescale, as reconstructed using the indirect proxy method. The concept of solar activity is discussed along with an overview of the dedicated indices used to quantify different aspects of variable solar activity, with special emphasis on sunspot numbers. Over long timescales, quantitative information about past solar activity is historically obtained using a method based on indirect proxies, such as cosmogenic isotopes <span>(^{14})</span>C and <span>(^{10})</span>Be in natural stratified archives (e.g., tree rings or ice cores). We give a historical overview of the development of the proxy-based method for past solar-activity reconstruction over millennia, as well as a description of the modern state of the art. Special attention is paid to the verification and cross-calibration of reconstructions. It is argued that the method of cosmogenic isotopes makes a solid basis for studies of solar variability in the past on a long timescale (centuries to millennia) during the Holocene (the past <span>(sim )</span>12 millennia). A separate section is devoted to reconstructions of extremely rare solar eruptive events in the past, based on both cosmogenic-proxy data in terrestrial and lunar natural archives, as well as statistics of sun-like stars. Finally, the main features of the long-term evolution of solar magnetic activity, including the statistics of grand minima and maxima occurrence, are summarized and their possible implications, especially for solar/stellar dynamo theory, are discussed.</p></div>","PeriodicalId":49147,"journal":{"name":"Living Reviews in Solar Physics","volume":"20 1","pages":""},"PeriodicalIF":20.9,"publicationDate":"2023-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s41116-023-00036-z.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4222132","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-07-15DOI: 10.1007/s41116-022-00034-7
Shravan M. Hanasoge
Solar meridional circulation is an axisymmetric flow system, extending from the equator to the poles ((sim )20 m/s at the surface, (approx )1% of the mean solar rotation rate), plunging inwards and subsequently completing the circuit in the interior through an equatorward return flow and a radially outward flow back up to the surface. This article reviews the profound role that meridional circulation plays in maintaining global dynamics and regulating large-scale solar magnetism. Because it is relatively weak in comparison to differential rotation ((sim )300 m/s, (approx )7% of the mean solar rotation rate) and owing to numerous systematical errors, accurate surface measurements were only first made in 1978 and initial inferences of interior meridional circulation were obtained using helioseismology two decades later. However, systematical biases have made it very challenging to reliably recover flow in the deep interior. Despite numerous advances that have served to improve the accuracy of inferences, the location of the return flow and the full extent of the circulation are still open problems. This article follows the historical developments and summarises contemporary advances that have led to modern inferences of surface and interior meridional flow.
太阳经向环流是一个轴对称的流动系统,从赤道向两极延伸((sim )地表20 m/s, (approx ) 1)% of the mean solar rotation rate), plunging inwards and subsequently completing the circuit in the interior through an equatorward return flow and a radially outward flow back up to the surface. This article reviews the profound role that meridional circulation plays in maintaining global dynamics and regulating large-scale solar magnetism. Because it is relatively weak in comparison to differential rotation ((sim )300 m/s, (approx )7% of the mean solar rotation rate) and owing to numerous systematical errors, accurate surface measurements were only first made in 1978 and initial inferences of interior meridional circulation were obtained using helioseismology two decades later. However, systematical biases have made it very challenging to reliably recover flow in the deep interior. Despite numerous advances that have served to improve the accuracy of inferences, the location of the return flow and the full extent of the circulation are still open problems. This article follows the historical developments and summarises contemporary advances that have led to modern inferences of surface and interior meridional flow.
{"title":"Surface and interior meridional circulation in the Sun","authors":"Shravan M. Hanasoge","doi":"10.1007/s41116-022-00034-7","DOIUrl":"10.1007/s41116-022-00034-7","url":null,"abstract":"<div><p>Solar meridional circulation is an axisymmetric flow system, extending from the equator to the poles (<span>(sim )</span>20 m/s at the surface, <span>(approx )</span>1% of the mean solar rotation rate), plunging inwards and subsequently completing the circuit in the interior through an equatorward return flow and a radially outward flow back up to the surface. This article reviews the profound role that meridional circulation plays in maintaining global dynamics and regulating large-scale solar magnetism. Because it is relatively weak in comparison to differential rotation (<span>(sim )</span>300 m/s, <span>(approx )</span>7% of the mean solar rotation rate) and owing to numerous systematical errors, accurate surface measurements were only first made in 1978 and initial inferences of interior meridional circulation were obtained using helioseismology two decades later. However, systematical biases have made it very challenging to reliably recover flow in the deep interior. Despite numerous advances that have served to improve the accuracy of inferences, the location of the return flow and the full extent of the circulation are still open problems. This article follows the historical developments and summarises contemporary advances that have led to modern inferences of surface and interior meridional flow.</p></div>","PeriodicalId":49147,"journal":{"name":"Living Reviews in Solar Physics","volume":"19 1","pages":""},"PeriodicalIF":23.0,"publicationDate":"2022-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s41116-022-00034-7.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138533648","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-11-03DOI: 10.1007/s41116-021-00031-2
Yuhong Fan
It has been a prevailing picture that active regions on the solar surface originate from a strong toroidal magnetic field stored in the overshoot region at the base of the solar convection zone, generated by a deep seated solar dynamo mechanism. This article reviews the studies in regard to how the toroidal magnetic field can destabilize and rise through the convection zone to form the observed solar active regions at the surface. Furthermore, new results from the global simulations of the convective dynamos, and from the near-surface layer simulations of active region formation, together with helioseismic investigations of the pre-emergence active regions, are calling into question the picture of active regions as buoyantly rising flux tubes originating from the bottom of the convection zone. This article also gives a review on these new developments.
{"title":"Magnetic fields in the solar convection zone","authors":"Yuhong Fan","doi":"10.1007/s41116-021-00031-2","DOIUrl":"10.1007/s41116-021-00031-2","url":null,"abstract":"<div><p>It has been a prevailing picture that active regions on the solar surface originate from a strong toroidal magnetic field stored in the overshoot region at the base of the solar convection zone, generated by a deep seated solar dynamo mechanism. This article reviews the studies in regard to how the toroidal magnetic field can destabilize and rise through the convection zone to form the observed solar active regions at the surface. Furthermore, new results from the global simulations of the convective dynamos, and from the near-surface layer simulations of active region formation, together with helioseismic investigations of the pre-emergence active regions, are calling into question the picture of active regions as buoyantly rising flux tubes originating from the bottom of the convection zone. This article also gives a review on these new developments.</p></div>","PeriodicalId":49147,"journal":{"name":"Living Reviews in Solar Physics","volume":"18 1","pages":""},"PeriodicalIF":23.0,"publicationDate":"2021-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s41116-021-00031-2.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138533654","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-06-29DOI: 10.1007/s41116-021-00030-3
Manuela Temmer
The Sun, as an active star, is the driver of energetic phenomena that structure interplanetary space and affect planetary atmospheres. The effects of Space Weather on Earth and the solar system is of increasing importance as human spaceflight is preparing for lunar and Mars missions. This review is focusing on the solar perspective of the Space Weather relevant phenomena, coronal mass ejections (CMEs), flares, solar energetic particles (SEPs), and solar wind stream interaction regions (SIR). With the advent of the STEREO mission (launched in 2006), literally, new perspectives were provided that enabled for the first time to study coronal structures and the evolution of activity phenomena in three dimensions. New imaging capabilities, covering the entire Sun-Earth distance range, allowed to seamlessly connect CMEs and their interplanetary counterparts measured in-situ (so called ICMEs). This vastly increased our knowledge and understanding of the dynamics of interplanetary space due to solar activity and fostered the development of Space Weather forecasting models. Moreover, we are facing challenging times gathering new data from two extraordinary missions, NASA’s Parker Solar Probe (launched in 2018) and ESA’s Solar Orbiter (launched in 2020), that will in the near future provide more detailed insight into the solar wind evolution and image CMEs from view points never approached before. The current review builds upon the Living Reviews article by Schwenn from 2006, updating on the Space Weather relevant CME-flare-SEP phenomena from the solar perspective, as observed from multiple viewpoints and their concomitant solar surface signatures.
{"title":"Space weather: the solar perspective","authors":"Manuela Temmer","doi":"10.1007/s41116-021-00030-3","DOIUrl":"https://doi.org/10.1007/s41116-021-00030-3","url":null,"abstract":"<p>The Sun, as an active star, is the driver of energetic phenomena that structure interplanetary space and affect planetary atmospheres. The effects of Space Weather on Earth and the solar system is of increasing importance as human spaceflight is preparing for lunar and Mars missions. This review is focusing on the solar perspective of the Space Weather relevant phenomena, coronal mass ejections (CMEs), flares, solar energetic particles (SEPs), and solar wind stream interaction regions (SIR). With the advent of the STEREO mission (launched in 2006), literally, new perspectives were provided that enabled for the first time to study coronal structures and the evolution of activity phenomena in three dimensions. New imaging capabilities, covering the entire Sun-Earth distance range, allowed to seamlessly connect CMEs and their interplanetary counterparts measured in-situ (so called ICMEs). This vastly increased our knowledge and understanding of the dynamics of interplanetary space due to solar activity and fostered the development of Space Weather forecasting models. Moreover, we are facing challenging times gathering new data from two extraordinary missions, NASA’s Parker Solar Probe (launched in 2018) and ESA’s Solar Orbiter (launched in 2020), that will in the near future provide more detailed insight into the solar wind evolution and image CMEs from view points never approached before. The current review builds upon the Living Reviews article by Schwenn from 2006, updating on the Space Weather relevant CME-flare-SEP phenomena from the solar perspective, as observed from multiple viewpoints and their concomitant solar surface signatures.</p>","PeriodicalId":49147,"journal":{"name":"Living Reviews in Solar Physics","volume":"18 1","pages":""},"PeriodicalIF":20.9,"publicationDate":"2021-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s41116-021-00030-3","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"5124369","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-04-26DOI: 10.1007/s41116-021-00029-w
Aline A. Vidotto
How has the solar wind evolved to reach what it is today? In this review, I discuss the long-term evolution of the solar wind, including the evolution of observed properties that are intimately linked to the solar wind: rotation, magnetism and activity. Given that we cannot access data from the solar wind 4 billion years ago, this review relies on stellar data, in an effort to better place the Sun and the solar wind in a stellar context. I overview some clever detection methods of winds of solar-like stars, and derive from these an observed evolutionary sequence of solar wind mass-loss rates. I then link these observational properties (including, rotation, magnetism and activity) with stellar wind models. I conclude this review then by discussing implications of the evolution of the solar wind on the evolving Earth and other solar system planets. I argue that studying exoplanetary systems could open up new avenues for progress to be made in our understanding of the evolution of the solar wind.
{"title":"The evolution of the solar wind","authors":"Aline A. Vidotto","doi":"10.1007/s41116-021-00029-w","DOIUrl":"https://doi.org/10.1007/s41116-021-00029-w","url":null,"abstract":"<p>How has the solar wind evolved to reach what it is today? In this review, I discuss the long-term evolution of the solar wind, including the evolution of observed properties that are intimately linked to the solar wind: rotation, magnetism and activity. Given that we cannot access data from the solar wind 4 billion years ago, this review relies on stellar data, in an effort to better place the Sun and the solar wind in a stellar context. I overview some clever detection methods of winds of solar-like stars, and derive from these an observed evolutionary sequence of solar wind mass-loss rates. I then link these observational properties (including, rotation, magnetism and activity) with stellar wind models. I conclude this review then by discussing implications of the evolution of the solar wind on the evolving Earth and other solar system planets. I argue that studying exoplanetary systems could open up new avenues for progress to be made in our understanding of the evolution of the solar wind.</p>","PeriodicalId":49147,"journal":{"name":"Living Reviews in Solar Physics","volume":"18 1","pages":""},"PeriodicalIF":20.9,"publicationDate":"2021-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s41116-021-00029-w","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4997258","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-04-26DOI: 10.1007/s41116-020-00028-3
Jørgen Christensen-Dalsgaard
The Sun provides a critical benchmark for the general study of stellar structure and evolution. Also, knowledge about the internal properties of the Sun is important for the understanding of solar atmospheric phenomena, including the solar magnetic cycle. Here I provide a brief overview of the theory of stellar structure and evolution, including the physical processes and parameters that are involved. This is followed by a discussion of solar evolution, extending from the birth to the latest stages. As a background for the interpretation of observations related to the solar interior I provide a rather extensive analysis of the sensitivity of solar models to the assumptions underlying their calculation. I then discuss the detailed information about the solar interior that has become available through helioseismic investigations and the detection of solar neutrinos, with further constraints provided by the observed abundances of the lightest elements. Revisions in the determination of the solar surface abundances have led to increased discrepancies, discussed in some detail, between the observational inferences and solar models. I finally briefly address the relation of the Sun to other similar stars and the prospects for asteroseismic investigations of stellar structure and evolution.
{"title":"Solar structure and evolution","authors":"Jørgen Christensen-Dalsgaard","doi":"10.1007/s41116-020-00028-3","DOIUrl":"https://doi.org/10.1007/s41116-020-00028-3","url":null,"abstract":"<p>The Sun provides a critical benchmark for the general study of stellar structure and evolution. Also, knowledge about the internal properties of the Sun is important for the understanding of solar atmospheric phenomena, including the solar magnetic cycle. Here I provide a brief overview of the theory of stellar structure and evolution, including the physical processes and parameters that are involved. This is followed by a discussion of solar evolution, extending from the birth to the latest stages. As a background for the interpretation of observations related to the solar interior I provide a rather extensive analysis of the sensitivity of solar models to the assumptions underlying their calculation. I then discuss the detailed information about the solar interior that has become available through helioseismic investigations and the detection of solar neutrinos, with further constraints provided by the observed abundances of the lightest elements. Revisions in the determination of the solar surface abundances have led to increased discrepancies, discussed in some detail, between the observational inferences and solar models. I finally briefly address the relation of the Sun to other similar stars and the prospects for asteroseismic investigations of stellar structure and evolution.</p>","PeriodicalId":49147,"journal":{"name":"Living Reviews in Solar Physics","volume":"18 1","pages":""},"PeriodicalIF":20.9,"publicationDate":"2021-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s41116-020-00028-3","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4990891","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-11DOI: 10.1007/s41116-020-00027-4
Thomas Wiegelmann, Takashi Sakurai
The structure and dynamics of the solar corona is dominated by the magnetic field. In most areas in the corona magnetic forces are so dominant that all non-magnetic forces such as plasma pressure gradients and gravity can be neglected in the lowest order. This model assumption is called the force-free field assumption, as the Lorentz force vanishes. This can be obtained by either vanishing electric currents (leading to potential fields) or the currents are co-aligned with the magnetic field lines. First we discuss a mathematically simpler approach that the magnetic field and currents are proportional with one global constant, the so-called linear force-free field approximation. In the generic case, however, the relationship between magnetic fields and electric currents is nonlinear and analytic solutions have been only found for special cases, like 1D or 2D configurations. For constructing realistic nonlinear force-free coronal magnetic field models in 3D, sophisticated numerical computations are required and boundary conditions must be obtained from measurements of the magnetic field vector in the solar photosphere. This approach is currently a large area of research, as accurate measurements of the photospheric field are available from ground-based observatories such as the Synoptic Optical Long-term Investigations of the Sun and the Daniel K. Inouye Solar Telescope (DKIST) and space-born, e.g., from Hinode and the Solar Dynamics Observatory. If we can obtain accurate force-free coronal magnetic field models we can calculate the free magnetic energy in the corona, a quantity which is important for the prediction of flares and coronal mass ejections. Knowledge of the 3D structure of magnetic field lines also help us to interpret other coronal observations, e.g., EUV images of the radiating coronal plasma.
{"title":"Solar force-free magnetic fields","authors":"Thomas Wiegelmann, Takashi Sakurai","doi":"10.1007/s41116-020-00027-4","DOIUrl":"https://doi.org/10.1007/s41116-020-00027-4","url":null,"abstract":"<p>The structure and dynamics of the solar corona is dominated by the magnetic field.\u0000 In most areas in the corona magnetic forces are so dominant that all non-magnetic forces such as plasma pressure gradients and gravity can be neglected in the lowest order. This model assumption is called the force-free field assumption, as the Lorentz force vanishes. This can be obtained by either vanishing electric currents (leading to potential fields) or the currents are co-aligned with the magnetic field lines. First we discuss a mathematically simpler approach that the magnetic field and currents are proportional with one global constant, the so-called linear force-free field approximation. In the generic case, however, the relationship between magnetic fields and electric currents is nonlinear and analytic solutions have been only found for special cases, like 1D or 2D configurations. For constructing realistic nonlinear force-free coronal magnetic field models in 3D, sophisticated numerical computations are required and boundary conditions must be obtained from measurements of the magnetic field vector in the solar photosphere.\u0000 This approach is currently a large area of research, as accurate measurements of the photospheric field are available from ground-based observatories such as the Synoptic Optical Long-term Investigations of the Sun and the Daniel K. Inouye Solar Telescope (DKIST) and space-born, e.g., from Hinode and the Solar Dynamics Observatory. If we can obtain accurate force-free coronal magnetic field models we can calculate the free magnetic energy in the corona, a quantity which is important for the prediction of flares and coronal mass ejections. Knowledge of the 3D structure of magnetic field lines also help us to interpret other coronal observations, e.g., EUV images of the radiating coronal plasma.</p>","PeriodicalId":49147,"journal":{"name":"Living Reviews in Solar Physics","volume":"18 1","pages":""},"PeriodicalIF":20.9,"publicationDate":"2021-01-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s41116-020-00027-4","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4457184","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-03-23DOI: 10.1007/s41116-020-0024-x
Jorrit Leenaarts
Nearly all energy generated by fusion in the solar core is ultimately radiated away into space in the solar atmosphere, while the remaining energy is carried away in the form of neutrinos. The exchange of energy between the solar gas and the radiation field is thus an essential ingredient of atmospheric modeling. The equations describing these interactions are known, but their solution is so computationally expensive that they can only be solved in approximate form in multi-dimensional radiation-MHD modeling. In this review, I discuss the most commonly used approximations for energy exchange between gas and radiation in the photosphere, chromosphere, and corona.
{"title":"Radiation hydrodynamics in simulations of the solar atmosphere","authors":"Jorrit Leenaarts","doi":"10.1007/s41116-020-0024-x","DOIUrl":"https://doi.org/10.1007/s41116-020-0024-x","url":null,"abstract":"<p>Nearly all energy generated by fusion in the solar core is ultimately radiated away into space in the solar atmosphere, while the remaining energy is carried away in the form of neutrinos. The exchange of energy between the solar gas and the radiation field is thus an essential ingredient of atmospheric modeling. The equations describing these interactions are known, but their solution is so computationally expensive that they can only be solved in approximate form in multi-dimensional radiation-MHD modeling. In this review, I discuss the most commonly used approximations for energy exchange between gas and radiation in the photosphere, chromosphere, and corona.</p>","PeriodicalId":49147,"journal":{"name":"Living Reviews in Solar Physics","volume":"17 1","pages":""},"PeriodicalIF":20.9,"publicationDate":"2020-03-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s41116-020-0024-x","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4899419","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-02-28DOI: 10.1002/9783527412723.ch2
J. Christensen-Dalsgaard
The Sun provides a critical benchmark for the general study of stellar structure and evolution. Also, knowledge about the internal properties of the Sun is important for the understanding of solar atmospheric phenomena, including the solar magnetic cycle. Here I provide a brief overview of the theory of stellar structure and evolution, including the physical processes and parameters that are involved. This is followed by a discussion of solar evolution, extending from the birth to the latest stages. As a background for the interpretation of observations related to the solar interior I provide a rather extensive analysis of the sensitivity of solar models to the assumptions underlying their calculation. I then discuss the detailed information about the solar interior that has become available through helioseismic investigations and the detection of solar neutrinos, with further constraints provided by the observed abundances of the lightest elements. Revisions in the determination of the solar surface abundances have led to increased discrepancies, discussed in some detail, between the observational inferences and solar models. I finally briefly address the relation of the Sun to other similar stars and the prospects for asteroseismic investigations of stellar structure and evolution.
{"title":"Solar structure and evolution","authors":"J. Christensen-Dalsgaard","doi":"10.1002/9783527412723.ch2","DOIUrl":"https://doi.org/10.1002/9783527412723.ch2","url":null,"abstract":"The Sun provides a critical benchmark for the general study of stellar structure and evolution. Also, knowledge about the internal properties of the Sun is important for the understanding of solar atmospheric phenomena, including the solar magnetic cycle. Here I provide a brief overview of the theory of stellar structure and evolution, including the physical processes and parameters that are involved. This is followed by a discussion of solar evolution, extending from the birth to the latest stages. As a background for the interpretation of observations related to the solar interior I provide a rather extensive analysis of the sensitivity of solar models to the assumptions underlying their calculation. I then discuss the detailed information about the solar interior that has become available through helioseismic investigations and the detection of solar neutrinos, with further constraints provided by the observed abundances of the lightest elements. Revisions in the determination of the solar surface abundances have led to increased discrepancies, discussed in some detail, between the observational inferences and solar models. I finally briefly address the relation of the Sun to other similar stars and the prospects for asteroseismic investigations of stellar structure and evolution.","PeriodicalId":49147,"journal":{"name":"Living Reviews in Solar Physics","volume":"18 1","pages":"1-189"},"PeriodicalIF":20.9,"publicationDate":"2020-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/9783527412723.ch2","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48939006","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-02-26DOI: 10.1007/s41116-020-0023-y
Rainer Arlt, José M. Vaquero
Sunspot observations are available in fairly good numbers since 1610, after the invention of the telescope. This review is concerned with those sunspot observations of which longer records and drawings in particular are available. Those records bear information beyond the classical sunspot numbers or group sunspot numbers. We begin with a brief summary on naked-eye sunspot observations, in particular those with drawings. They are followed by the records of drawings from 1610 to about 1900. The review is not a compilation of all known historical sunspot information. Some records contributing substantially to the sunspot number time series may therefore be absent. We also glance at the evolution of the understanding of what sunspots actually are, from 1610 to the 19th century. The final part of the review illuminates the physical quantities that can be derived from historical drawings.
{"title":"Historical sunspot records","authors":"Rainer Arlt, José M. Vaquero","doi":"10.1007/s41116-020-0023-y","DOIUrl":"https://doi.org/10.1007/s41116-020-0023-y","url":null,"abstract":"<p>Sunspot observations are available in fairly good numbers since 1610, after the invention of the telescope. This review is concerned with those sunspot observations of which longer records and drawings in particular are available. Those records bear information beyond the classical sunspot numbers or group sunspot numbers. We begin with a brief summary on naked-eye sunspot observations, in particular those with drawings. They are followed by the records of drawings from 1610 to about 1900. The review is not a compilation of all known historical sunspot information. Some records contributing substantially to the sunspot number time series may therefore be absent. We also glance at the evolution of the understanding of what sunspots actually are, from 1610 to the 19th century. The final part of the review illuminates the physical quantities that can be derived from historical drawings.</p>","PeriodicalId":49147,"journal":{"name":"Living Reviews in Solar Physics","volume":"17 1","pages":""},"PeriodicalIF":20.9,"publicationDate":"2020-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s41116-020-0023-y","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4998012","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}