Solar Physics最新文献

{"title":"Aditya-L1 - An Observatory Class Mission: Spacecraft, Mission, and Operations","authors":"Nashiket Premlal Parate,&nbsp;Nigar Shaji,&nbsp;Motamarri Srikanth,&nbsp;K. Sankarasubramanian,&nbsp;Narashimha Murthy Patnaik,&nbsp;S. Narendra,&nbsp;Abhijit Avinash Adoni,&nbsp;Kuldeep Negi,&nbsp;Pragyan Pattanaik,&nbsp;Bharat Kumar G. V. P,&nbsp;Vivek R. Subramanian,&nbsp;Hemanth Kumar Reddy N.,&nbsp;Shree Niwas Sahu,&nbsp;Vishnu Kishore Pai,&nbsp;Sajjade Faisal Mustafa,&nbsp;Richa Pathak,&nbsp;Amit Maji,&nbsp;T. R. Haridas,&nbsp;Anand Raj,&nbsp;Pankaj Agarwal,&nbsp;Arvind Kumar Singh,&nbsp;Smruti Ranjan Panigrahi,&nbsp;A. Ravi","doi":"10.1007/s11207-025-02533-w","DOIUrl":"10.1007/s11207-025-02533-w","url":null,"abstract":"<div><p>Aditya-L1 is an observatory class mission designed and developed by the Indian Space Research Organisation (ISRO) to study the Sun and the inner heliosphere. Aditya-L1, currently orbiting around the first Lagrange point L1, is in a periodic halo orbit located approximately at 1.5 million km from Earth on the Sun–Earth line (about 1% of the Sun-Earth distance and closer to Earth). The orbital parameters of Aditya-L1 around L1 are Ax = 208,951 km, Ay = 670,024 km and Az = 120,000 km, where Ax, Ay and Az are semi-diameters of the orbit with an orbital period of 177.86 days. The primary objective of the Aditya-L1 mission is to understand the coronal and chromospheric dynamics of the Sun along with its influence on the heliosphere, especially at the L1 location. To achieve these goals, the spacecraft is configured to accommodate seven payloads of which four are remote sensing and three are in situ experiments. The scientific payloads are designed and developed by various Indian Research Institutes in close collaboration with different ISRO centers. The spacecraft is configured with the modified Mars orbiter mission (MOM) bus and is a three-axis stabilized spacecraft with a lift of mass of 1480.73 kg and power generation of ≈ 1820 W. Pointing stability will be better than 15 arcsec as required by the coronagraph payload. Aditya-L1 payload produces around 240 Gbits of science data per day (≈ 90% data is from the imaging payloads). Planning, coordination, and operation of the spacecraft and the scientific payloads are conducted from ISRO telemetry, tracking, and command network in Bengaluru, India. Aditya-L1 was launched on board the Polar Satellite Launch Vehicle (PSLV C57) at 11:50 Indian standard time (IST) from the second launch pad of the Satish Dhawan Space Centre (SDSC), Sriharikota, India on 2 September 2023. It was inserted at the L1 point on 6 January 2024, at 4:17 pm IST. The spacecraft, mission, and operation aspects of the Aditya-L1 spacecraft are discussed in this paper.</p></div>","PeriodicalId":777,"journal":{"name":"Solar Physics","volume":"300 9","pages":""},"PeriodicalIF":2.4,"publicationDate":"2025-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145062135","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}

{"title":"Automatic Detection of Ellerman Bombs in the H(alpha ) Line","authors":"Arooj Faryad,&nbsp;Alexander G. M. Pietrow,&nbsp;Meetu Verma,&nbsp;Carsten Denker","doi":"10.1007/s11207-025-02534-9","DOIUrl":"10.1007/s11207-025-02534-9","url":null,"abstract":"<div><p>Ellerman bombs (EBs) are small and short-lived magnetic reconnection events in the lower solar atmosphere, most commonly reported in the line wings of the H<span>(alpha )</span> line. These events are thought to play a role in heating the solar chromosphere and corona, but their size, short lifetime, and similarity to other brightenings make them difficult to detect. We aim to automatically detect and statistically analyze EBs at different heliocentric angles to find trends in their physical properties. We developed an automated EB detection pipeline based on a star-finding algorithm. This pipeline was used on ten high-resolution H<span>(alpha )</span> datasets from the 1-meter Swedish Solar Telescope (SST). This pipeline identifies and tracks EBs in time, while separating them from visually similar pseudo-EBs. It returns key parameters such as size, contrast, lifetime, and occurrence rates based on a dynamic threshold and the more classical static ‘contrast threshold’ of 1.5 times the mean quiet-Sun (QS) intensity. For our dynamic threshold we found a total of 2257 EBs from 28,772 individual detections across our datasets. On average, the full detection set exhibits an area of 0.44 arcsec² (0.37 Mm²), a peak intensity contrast of 1.4 relative to the QS, and a median lifetime of 2.3 min. The stricter threshold yielded 549 EBs from 15,997 detections, with a higher median area of 0.66 arcsec² (0.57 Mm²), an intensity contrast of 1.7, and a median lifetime of 3 min. These comparisons highlight the sensitivity of EB statistics to selection thresholds and motivate further work towards consistent EB definitions. Several long-lived EBs were observed with lifetimes exceeding one hour. While the EB intensity contrast increases towards the limb, no clear trends were found between the other EB parameters and the heliocentric angle, suggesting that the local magnetic complexity and evolutionary stage dominate EB properties.</p></div>","PeriodicalId":777,"journal":{"name":"Solar Physics","volume":"300 9","pages":""},"PeriodicalIF":2.4,"publicationDate":"2025-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145028157","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}

{"title":"Incorporating Magnetic-Field Characteristics into EUV-Based Automated Segmentation of Coronal Holes","authors":"Jeremy A. Grajeda,&nbsp;Laura E. Boucheron,&nbsp;Michael S. Kirk,&nbsp;Andrew Leisner,&nbsp;Jaime A. Landeros,&nbsp;C. Nick Arge","doi":"10.1007/s11207-025-02536-7","DOIUrl":"10.1007/s11207-025-02536-7","url":null,"abstract":"<div><p>Coronal holes (CHs) are magnetically open regions that allow hot coronal plasma to escape from the Sun and form the high-speed solar wind. This wind can interact with Earth’s magnetic field. For this reason, developing an accurate understanding of CH regions is vital for understanding space weather and its effects on Earth. The process of identifying CH regions typically relies on extreme ultraviolet (EUV) imagery, leveraging the fact that CHs appear dark at these wavelengths. Accurate identification of CHs in EUV, however, can be difficult due to a variety of factors, including stray light from nearby regions, limb brightening, and the presence of filaments (which also appear dark, but are not sources of solar wind). In order to overcome these issues, this work incorporates photospheric magnetic-field data into a classical EUV-based segmentation algorithm based on the Active Contours Without Edges (ACWE) segmentation method. In this work magnetic-field data are incorporated directly into the segmentation process, serving both as a method for removing non-CH regions in advance, and as a method to constrain evolution of the segmented CH boundary. This reduces the presence of filaments while allowing the segmentation to include CH regions that may be difficult to identify due to inconsistent intensities.</p></div>","PeriodicalId":777,"journal":{"name":"Solar Physics","volume":"300 9","pages":""},"PeriodicalIF":2.4,"publicationDate":"2025-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s11207-025-02536-7.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145011824","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}

{"title":"Direct Observational Evidence of Solar Wind Density Controlling the Evolution of the Ring Current During the 2024 October Major Storm","authors":"Ming-Xian Zhao,&nbsp;Gui-Ming Le","doi":"10.1007/s11207-025-02539-4","DOIUrl":"10.1007/s11207-025-02539-4","url":null,"abstract":"<div><p>We investigated the interplanetary source of the October 2024 major storm and determined that it was triggered by a sheath region and a magnetic cloud (MC), with the sheath region playing a decisive role. The MC has a larger and longer duration of southward interplanetary magnetic field (IMF) and solar wind electric field compared to the sheath, and the largest southward IMF and solar wind electric field were observed within the MC. As expect, the solar wind density in the sheath region is much larger than that in the MC. The results of this study not only provide direct evidence that solar wind density controls the evolution of the ring current, but also demonstrate that the correlation coefficients between the largest southward IMF and geomagnetic storm intensity, as well as between the largest solar wind electric field and geomagnetic storm intensity, lack physical meaning. The contribution of the sheath region to the intensity of the major storm, as estimated by the empirical formula developed by Burton, McPherron, and Russell (1975) (hereafter referred to as the BMR equation), was found to be smaller than that of the MC. However, actual observations indicate the opposite. This discrepancy suggests that the BMR equation is not capable of accurately estimating the ring current variation. The injection term in the BMR equation is merely a linear function of the solar wind electric field, without considering the solar wind density. This indicates that if we overlook the influence of solar wind density on the evolution of the ring current, estimating the intensity of a geomagnetic storm based solely on the integral of the solar wind electric field during the main phase of the storm would yield incorrect results. The October 2024 major storm also provides direct evidence that solar wind velocity, density, and the southward component of the IMF are all important parameters in the evolution of the ring current.</p></div>","PeriodicalId":777,"journal":{"name":"Solar Physics","volume":"300 9","pages":""},"PeriodicalIF":2.4,"publicationDate":"2025-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144934652","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}

{"title":"Recovery of the Solar Cycle from Maunder-Like Grand Minima Episodes: A Quantification of the Necessary Polar Flux Threshold Through Solar Dynamo Simulations","authors":"Chitradeep Saha,&nbsp;Sanghita Chandra,&nbsp;Dibyendu Nandy","doi":"10.1007/s11207-025-02538-5","DOIUrl":"10.1007/s11207-025-02538-5","url":null,"abstract":"<div><p>The 11-yr cycle of sunspots undergoes amplitude modulation over longer timescales. As a part of this long-term modulation in solar activity, the decennial rhythm occasionally breaks, with quiescent phases with very few sunspots observed over multiple decades. These episodes are termed as solar grand minima. Observation of solar magnetic activity proxies complemented by solar dynamo simulations suggests that the large-scale solar polar fields become very weak during these minima phases with a temporary halt in the polar field reversal. Eventually, with the accumulation of sufficient polar fluxes, the polarity reversal and regular cyclic activity is thought to resume, Using multi-millennial dynamo simulations with stochastic forcing, we quantify the polar flux threshold necessary to recover global solar polarity reversal and surmount grand minima phases. We find that the duration of a grand minimum is independent of the onset rate and does not affect the recovery rate. Our results suggest a method to forecast the Sun’s recovery from a grand minima phase. However, based on our approach, we could not identify specific precursors that signal entry in to a grand minima phase – implying that predicting the onset of grand minima remains an outstanding challenge.</p></div>","PeriodicalId":777,"journal":{"name":"Solar Physics","volume":"300 9","pages":""},"PeriodicalIF":2.4,"publicationDate":"2025-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144934651","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}

{"title":"Correlation of Coronal Hole Area Indices and Solar Wind Speed","authors":"Egor Illarionov,&nbsp;Andrey Tlatov,&nbsp;Ivan Berezin,&nbsp;Nadezhda Skorbezh","doi":"10.1007/s11207-025-02530-z","DOIUrl":"10.1007/s11207-025-02530-z","url":null,"abstract":"<div><p>Coronal holes (CHs) are widely considered as the main sources of high-speed solar wind streams. We validate this thesis comparing the smoothed time series of solar wind speed measured by the Advanced Composition Explorer (ACE) and various indices of CH areas constructed from the CH catalog compiled at the Kislovodsk Mountain Astronomical Station for the period 2010 – 2025. The main result is that we find specific indices of CH areas that give a strong correlation with smoothed solar wind speed variations. As an example, 1-year averaged areas of CHs located within 30 degrees of the solar equator yield a correlation of 0.9 with 1-year averaged solar wind speed. This strong correlation is a feature of the particular CH catalog, and considering an alternative CH catalog obtained using the Spatial Possibilistic Clustering Algorithm (SPoCA) from the Heliophysics Event Knowledgebase (HEK), the same index provides a correlation of only 0.3. Although the fact that the correlation significantly depends on the catalog requires a separate discussion, we conclude that if some of the catalogs can be used to construct a reliable indicator of solar wind speed variations, then this methodology should be maintained further. Additionally, we present time-latitude diagrams of rolling correlation between CH areas and solar wind speed, which, in our opinion, can be used to reveal source CHs for high-speed solar wind streams.</p></div>","PeriodicalId":777,"journal":{"name":"Solar Physics","volume":"300 9","pages":""},"PeriodicalIF":2.4,"publicationDate":"2025-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144929226","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}

{"title":"Statistical Analysis of Sunspot Area and Magnetic Flux on Solar Disc During 2011 – 2023","authors":"Avneesh Kumar,&nbsp;Nagendra Kumar,&nbsp;Hari Om Vats","doi":"10.1007/s11207-025-02537-6","DOIUrl":"10.1007/s11207-025-02537-6","url":null,"abstract":"<div><p>We investigate the temporal variations and distribution functions of daily sunspot area and magnetic flux data from 2011 to 2023. The yearly distribution of sunspot area on the solar full disc, southern hemisphere and northern hemisphere, and magnetic flux on the solar full disc are positively skewed for all the years from 2011 to 2023. We analyzed the variations of yearly maximum, median, first quartile, third quartile, interquartile range and mean of the daily sunspot area and magnetic flux on the solar full disc and found their maxima and minima for sunspot area and magnetic flux. Maxima occur in the years 2014 and 2015 for sunspot area and magnetic flux, respectively, whereas their minima occur in the years 2018 and 2019. We found the correlations between the descriptive statistical measures of sunspot area and magnetic flux, kernel density estimator, and lognormal functions to describe the distributions of daily sunspot area and magnetic flux. We found a positive correlation of 0.96 between the distribution functions of sunspot area and magnetic flux on the solar full disc during 2011 – 2023. We demonstrated that the distribution function for daily sunspot area correlates linearly well with the distribution function for magnetic flux during 2011 – 2023.</p></div>","PeriodicalId":777,"journal":{"name":"Solar Physics","volume":"300 9","pages":""},"PeriodicalIF":2.4,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144923093","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}

{"title":"Statistical Analysis of Solar Flare Properties from 1975 to 2017","authors":"L. Biasiotti,&nbsp;S. L. Ivanovski","doi":"10.1007/s11207-025-02532-x","DOIUrl":"10.1007/s11207-025-02532-x","url":null,"abstract":"<div><p>The statistical analysis of solar flares is essential for understanding their characteristics and properties, serving as a fundamental tool to interpret flare distributions and constrain the physical mechanisms driving their occurrence. In this paper, we investigated the statistical properties of these energetic phenomena over the last four solar cycles, spanning the period from September 1975 to June 2017. Specifically, we analysed the temporal (i.e., waiting time and duration) and energetic (i.e., peak intensity) aspects of soft X-ray (SXR) flares from the GOES catalogue in terms of flare occurrence rates and frequency distributions. We found that (i) the duration of most of the events increases with the increase of the intensity of a given flare, i.e. with its class. X-class flares exhibit a second peak centred around the 80th minute after its formation. (ii) Waiting times, i.e. the interval between the starting time of two consecutive flares, correlate with the solar activity variation within the solar cycle. (iii) In all solar cycles considered here, the flare and CME waiting-time distributions (WTDs) show similar power-law indices of the frequency event distribution and time variation, especially in the tail of the power-law distribution. (iv) Peak-intensity energy does not correlate with the waiting time, contrary to the idea that the more time elapses between two consecutive events the higher the intensity of the flare is.</p></div>","PeriodicalId":777,"journal":{"name":"Solar Physics","volume":"300 8","pages":""},"PeriodicalIF":2.4,"publicationDate":"2025-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s11207-025-02532-x.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144905255","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}

{"title":"Synthetic Resonance and Thomson Scattering of a Chromospheric (text{Ly}alpha ) Profile Using the Bastille Day CME Model Corona: Part 1","authors":"Nelson Reginald,&nbsp;Lutz Rastaetter","doi":"10.1007/s11207-025-02529-6","DOIUrl":"10.1007/s11207-025-02529-6","url":null,"abstract":"<div><p>In this article, Part 1, we have synthetically resonance scattered and Thomson scattered a measured solar chromospheric <span>(mathrm{Ly}alpha )</span> spectral radiance (CLSR) spectrum off the neutral hydrogen [<span>(N_{1})</span>] atoms in ground state and free electrons [<span>(N_{mathrm{e}})</span>], respectively, contained in a 3D coronal model of the 14 July 2000 (“Bastille Day”) <i>Coronal Mass Ejection</i> (CME). From these two scatters, we have computed maps of the associated resonance scattered spectral radiance (RSSR) spectrum and the Thomson scattered spectral radiance (TSSR) spectrum in ultraviolet (UV) from 121.3 to 121.8 nm with a wavelength resolution of 0.1 nm, which encompasses the <span>(mathrm{Ly}alpha )</span> center line at 121.57 nm. We then integrated the maps over the above wavelength range and have created two 2D resonance scattered radiance (RSR) and Thomson scattered radiance (TSR) maps. As expected, the TSSR spectrum is <span>(approx 1000)</span> times dimmer than the RSSR spectrum, which we can deem for it to contribute towards noise in the center of the RSSR spectrum. In a follow up article, Part 2, we intend to do the following with these maps. First, we will use the computed RSSR spectra along each line of sight (LOS) to derive the proton temperature [<span>(T_{mathrm{p}})</span>] and speed [<span>(V_{mathrm{p}})</span>] using the Doppler Dimming technique (DDT). Second, we will compare these derived proton parameters along each LOS with the actual values contained within the Bastille Day CME model at the plane of the sky and compute the differences. If we find they are different we will then determine where along the LOS they closely match and their distances from the plane of the sky. Finally, we will quantify an estimate of the systematic error from using DDT to measure the proton parameters at the plane of the sky, which is different from the statistical error margins reported in the literature from real RSSR experiments conducted from space-based instruments.</p></div>","PeriodicalId":777,"journal":{"name":"Solar Physics","volume":"300 8","pages":""},"PeriodicalIF":2.4,"publicationDate":"2025-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144894024","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}

{"title":"Multispacecraft Observations of the 2024 September 9 Backside Solar Eruption That Resulted in a Sustained Gamma Ray Emission Event","authors":"Nat Gopalswamy,&nbsp;Pertti Mäkelä,&nbsp;Sachiko Akiyama,&nbsp;Hong Xie,&nbsp;Seiji Yashiro,&nbsp;Stuart D. Bale,&nbsp;Robert F. Wimmer-Schweingruber,&nbsp;Patrick Kühl,&nbsp;Säm Krucker","doi":"10.1007/s11207-025-02526-9","DOIUrl":"10.1007/s11207-025-02526-9","url":null,"abstract":"<div><p>We report on the 2024 September 9 sustained gamma-ray emission (SGRE) event observed by the Large Area Telescope (LAT) on board the Fermi satellite. The hevent was associated with a backside solar eruption observed by multiple spacecraft such as the Solar and Heliospheric Observatory (SOHO), Solar Terrestrial Relations Observatory (STEREO), Parker Solar Probe (PSP), Solar Orbiter (SolO), Solar Dynamics Observatory (SDO), Wind, and GOES, and by ground-based radio telescopes. Fermi/LAT observed the SGRE after the EUV wave from the backside eruption crossed the limb to the frontside of the Sun. SolO’s Spectrometer Telescope for Imaging X-rays (STIX) imaged an intense (X3.3) flare, which occurred ≈ 41° behind the east limb, from heliographic coordinates S13E131. Forward modeling of the coronal mass ejection (CME) flux rope revealed that it impulsively accelerated (3.54 km s⁻²) to attain a peak speed of 2162 km s⁻¹. SolO’s energetic particle detectors (EPD) observed protons up to ≈ 1 GeV from the extended shock and electrons that produced a complex type II burst and possibly type III bursts. The durations of SGRE and type II burst are consistent with the linear relation between these quantities obtained from longer duration (&gt; 3 hours) SGRE events. All these observations are consistent with an extended shock surrounding the CME flux rope, which is the likely source of high-energy protons required for the SGRE event. We compare this event with six other behind-the-limb (BTL) SGRE eruptions and find that they are all consistent with energetic shock-driving CMEs. We also find a significant east-west asymmetry (3:1) in the BTL source locations.</p></div>","PeriodicalId":777,"journal":{"name":"Solar Physics","volume":"300 8","pages":""},"PeriodicalIF":2.4,"publicationDate":"2025-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s11207-025-02526-9.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144894025","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}