Solar Physics最新文献

{"title":"CATEcor: An Open Science, Shaded-Truss, Externally-Occulted Coronagraph","authors":"Craig DeForest,&nbsp;Daniel B. Seaton,&nbsp;Amir Caspi,&nbsp;Matt Beasley,&nbsp;Sarah J. Davis,&nbsp;Nicholas F. Erickson,&nbsp;Sarah A. Kovac,&nbsp;Ritesh Patel,&nbsp;Anna Tosolini,&nbsp;Matthew J. West","doi":"10.1007/s11207-024-02314-x","DOIUrl":"10.1007/s11207-024-02314-x","url":null,"abstract":"<div><p>We present the design of a portable coronagraph, CATEcor (where CATE stands for Continental-America Telescope Eclipse), that incorporates a novel “shaded-truss” style of external occultation and serves as a proof-of-concept for that family of coronagraphs. The shaded-truss design style has the potential for broad application in various scientific settings. We conceived CATEcor itself as a simple instrument to observe the corona during the darker skies available during a partial solar eclipse, or for students or interested amateurs to detect the corona under ideal noneclipsed conditions. CATEcor is therefore optimized for simplicity and accessibility to the public. It is implemented using an existing dioptric telescope and an adapter rig that mounts in front of the objective lens, restricting the telescope aperture and providing external occultation. The adapter rig, including occulter, is fabricated using fusion deposition modeling (FDM; colloquially “3D printing”), greatly reducing cost. The structure is designed to be integrated with moderate care and may be replicated in a university or amateur setting. While CATEcor is a simple demonstration unit, the design concept, process, and trades are useful for other more sophisticated coronagraphs in the same general family, which might operate under normal daytime skies outside the annular-eclipse conditions used for CATEcor.</p></div>","PeriodicalId":777,"journal":{"name":"Solar Physics","volume":"299 6","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11164819/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141309407","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":"The Dispersion Relation for Waves in a Magnetic Flux Tube","authors":"B. Roberts","doi":"10.1007/s11207-024-02320-z","DOIUrl":"10.1007/s11207-024-02320-z","url":null,"abstract":"<div><p>A recent discussion (Yelagandula, 2023) of waves in a magnetic flux tube questions the use of the normal velocity continuity condition in the derivation of the standard dispersion relation. We re-assert this condition here.</p></div>","PeriodicalId":777,"journal":{"name":"Solar Physics","volume":"299 6","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s11207-024-02320-z.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141413598","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":"The Basic Iterative Deconvolution: A Fast Instrumental Point-Spread Function Deconvolution Method That Corrects for Light That Is Scattered Out of the Field of View of a Detector","authors":"Stefan Johann Hofmeister","doi":"10.1007/s11207-024-02321-y","DOIUrl":"10.1007/s11207-024-02321-y","url":null,"abstract":"<div><p>A point-spread function describes the optics of an imaging system and can be used to correct collected images for instrumental effects. The state of the art for deconvolving images with the point-spread function is the Richardson–Lucy algorithm; however, despite its high fidelity, it is slow and cannot account for light scattered out of the field of view of the detector. We reinstate the Basic Iterative Deconvolution (BID) algorithm, a deconvolution algorithm that considers photons scattered out of the field of view of the detector, and extend it for image subregion deconvolutions. Its runtime is 1.8 to 7.1 faster than the Richardson–Lucy algorithm for <span>(4096 times 4096)</span> pixel images and up to an additional factor of 150 for subregions of <span>(250 times 250)</span> pixels. We test the extended BID algorithm for solar images taken by the Atmospheric Imaging Assembly (AIA), and find that the reconstructed intensities between BID and the Richardson–Lucy algorithm agree within 1%.</p></div>","PeriodicalId":777,"journal":{"name":"Solar Physics","volume":"299 6","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141513300","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":"A Catalog of Metric Type II Radio Bursts Detected by RSTN During Solar Cycle 24","authors":"Bendict Lawrance,&nbsp;Pooja Devi,&nbsp;Ramesh Chandra,&nbsp;Rositsa Miteva","doi":"10.1007/s11207-024-02317-8","DOIUrl":"10.1007/s11207-024-02317-8","url":null,"abstract":"<div><p>In this study, we compile a catalog of metric type II radio bursts using the <i>Radio Solar Telescope Network</i> (RSTN) to study the occurrence, associations, and properties of the emission and their parent solar activity phenomena. According to the intensity and clarity of the radio emission features, we have divided the m-type II radio bursts into two qualitative categories, namely certain and uncertain. We analyzed RSTN data in Solar Cycle 24 (2009 – 2019), which is freely available from four worldwide stations: Learmonth, Sanvito, Sagamore Hills, and Palehua. Through careful visual inspection, we have collected all metric type II bursts detected in the range of 25 – 180 MHz. The relationships between these bursts and solar eruptive events, such as solar flares and coronal mass ejections (CMEs), are studied, and the results are presented and discussed. The outcomes could be used to reveal the occurrence of solar and space-weather activities based on the ground-based radio perspective. The newly assembled catalog of metric type II and associated solar events will be made freely available to the solar scientific community.</p></div>","PeriodicalId":777,"journal":{"name":"Solar Physics","volume":"299 6","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141258470","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":"Origin of the Chromospheric Umbral Waves in Sunspots","authors":"Xinsheng Zhang,&nbsp;Xiaoli Yan,&nbsp;Zhike Xue,&nbsp;Jincheng Wang,&nbsp;Zhe Xu,&nbsp;Qiaoling Li,&nbsp;Yang Peng,&nbsp;Liping Yang","doi":"10.1007/s11207-024-02323-w","DOIUrl":"10.1007/s11207-024-02323-w","url":null,"abstract":"<div><p>Oscillations are ubiquitous in sunspots and the associated higher atmospheres. However, it is still unclear whether these oscillations are driven by the external acoustic waves (p-modes) or generated by the internal magnetoconvection. To obtain clues about the driving source of umbral waves in sunspots, we analyzed the spiral wave patterns (SWPs) in two sunspots registered by IRIS MgII 2796 Å slit-jaw images. By tracking the motion of the SWPs, we found for the first time that two one-armed SWPs coexist in the umbra, and they can rotate either in the same or opposite directions. Furthermore, by analyzing the spatial distribution of the oscillation centers of the one-armed SWPs within the umbra (the oscillation center is defined as the location where the SWP first appears), we found that the chromospheric umbral waves repeatedly originate from the regions with high oscillation power and most of the umbral waves occur in the dark nuclei and strong magnetic field regions of the umbra. Our study results indicate that the chromospheric umbral waves are likely excited by the p-mode oscillations.</p></div>","PeriodicalId":777,"journal":{"name":"Solar Physics","volume":"299 5","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141167391","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":"Spectral and Imaging Observations of a C2.3 White-Light Flare from the Advanced Space-Based Solar Observatory (ASO-S) and the Chinese H(alpha ) Solar Explorer (CHASE)","authors":"Qiao Li,&nbsp;Ying Li,&nbsp;Yang Su,&nbsp;Dechao Song,&nbsp;Hui Li,&nbsp;Li Feng,&nbsp;Yu Huang,&nbsp;Youping Li,&nbsp;Jingwei Li,&nbsp;Jie Zhao,&nbsp;Lei Lu,&nbsp;Beili Ying,&nbsp;Jianchao Xue,&nbsp;Ping Zhang,&nbsp;Jun Tian,&nbsp;Xiaofeng Liu,&nbsp;Gen Li,&nbsp;Zhichen Jing,&nbsp;Shuting Li,&nbsp;Guanglu Shi,&nbsp;Zhengyuan Tian,&nbsp;Wei Chen,&nbsp;Yingna Su,&nbsp;Qingmin Zhang,&nbsp;Dong Li,&nbsp;Yunyi Ge,&nbsp;Jiahui Shan,&nbsp;Yue Zhou,&nbsp;Shijun Lei,&nbsp;Weiqun Gan","doi":"10.1007/s11207-024-02313-y","DOIUrl":"10.1007/s11207-024-02313-y","url":null,"abstract":"<div><p>Solar white-light flares are characterized by an enhancement in the optical continuum, which are usually large flares (X- and M-class flares). Here, we report a small C2.3 white-light flare (SOL2022-12-20T04:10) observed by the <i>Advanced Space-based Solar Observatory</i> and the <i>Chinese H</i><span>(alpha )</span> <i>Solar Explorer</i> (CHASE). This flare exhibits an increase of ≈ 6.4% in the photospheric Fe <span>i</span> line at 6569.2 Å and ≈ 3.2% in the nearby continuum. The continuum at 3600 Å also shows an enhancement of ≈ 4.7%. The white-light bright kernels are mainly located at the flare ribbons and co-spatial with nonthermal hard X-ray sources, which implies that the enhanced white-light emissions are related to nonthermal electron-beam heating. At the bright kernels, the Fe <span>i</span> line displays an absorption profile that has a good Gaussian shape, with a redshift up to ≈ 1.7 km s⁻¹, while the H<span>(alpha )</span> line shows an emission profile having a central reversal. The H<span>(alpha )</span> line profile also shows a red or blue asymmetry caused by plasma flows with a velocity of several to tens of km s⁻¹. It is interesting to find that the H<span>(alpha )</span> asymmetry is opposite at the conjugate footpoints. It is also found that the CHASE continuum increase seems to be related to the change in the photospheric magnetic field. Our study provides comprehensive characteristics of a small white-light flare that help understand the energy release process of white-light flares.</p></div>","PeriodicalId":777,"journal":{"name":"Solar Physics","volume":"299 5","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s11207-024-02313-y.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141192374","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":"Properties of Type-II Radio Bursts in Relation to Magnetic Complexity of the Solar Active Regions","authors":"Tusharkumar N. Bhatt,&nbsp;Rajmal Jain,&nbsp;N. Gopalswamy,&nbsp;Anjali Dwivedi,&nbsp;Anshupriya Singh,&nbsp;Arun Kumar Awasthi,&nbsp;Seiji Yashiro,&nbsp;Walter R. Guevara Day,&nbsp;Pramod K. Chamadia,&nbsp;Krunal Patel,&nbsp;Sneha Chaudhari","doi":"10.1007/s11207-024-02318-7","DOIUrl":"10.1007/s11207-024-02318-7","url":null,"abstract":"<div><p>Type-II radio bursts are believed to occur as a result of the shock driven by flares or coronal mass ejections (CMEs). While the shock waves are important for the acceleration of electrons necessary for the generation of the radio emission, the exact nature of the shock and coronal conditions necessary to produce type-II radio emission is still under debate. In this investigation, we probe the relationship of kinematic characteristics of the type-II radio bursts with the magnetic-field complexity (<i>M</i>_<i>j</i>) of the active regions visible on the photosphere. Our investigation of 64 type-II solar radio bursts, which are associated with flares and CMEs, reveals that <i>M</i>_<i>j</i> is linearly correlated in the logarithmic scale with the starting frequency (<i>f</i>_s) and drift-rate (<span>({Delta f/Delta t})</span>) of type-II radio burst. Further, <i>M</i>_<i>j</i> exhibits a linear correlation with the shock height (<i>r</i>) and electron density (<span>(n_{rm e})</span>) in logarithmic scale. This indicates that high frequency (<i>f</i>_s <span>(geq 100)</span> <span>({rm MH_{z}})</span>) bursts, which occur at the reconnection site near the solar surface, are produced from a strong magnetically complex region. Further, strong and complex magnetic-field regions produce shocks of higher speeds. Based on the derived plasma parameters of the radio bursts and their relationship with <i>f</i>_s as well as with <i>M</i>_<i>j</i>, we propose that the high-frequency type-II bursts were generated in a special situation when the shock is produced due to magnetic reconnection occurring in the low-lying coronal loops. We conclude that type-II radio bursts can occur even in the inner corona as well as in the outer corona; however, it depends on the magnetic complexity of the active region in which the event occurs.</p></div>","PeriodicalId":777,"journal":{"name":"Solar Physics","volume":"299 5","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s11207-024-02318-7.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141192388","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":"Automatic Solar Flare Detection Using the Solar Disk Imager Onboard the ASO-S Mission","authors":"Lei Lu,&nbsp;Zhengyuan Tian,&nbsp;Li Feng,&nbsp;Jiahui Shan,&nbsp;Hui Li,&nbsp;Yang Su,&nbsp;Ying Li,&nbsp;Yu Huang,&nbsp;Youping Li,&nbsp;Jingwei Li,&nbsp;Jie Zhao,&nbsp;Beili Ying,&nbsp;Jianchao Xue,&nbsp;Ping Zhang,&nbsp;Dechao Song,&nbsp;Shuting Li,&nbsp;Guanglu Shi,&nbsp;Yingna Su,&nbsp;Qingmin Zhang,&nbsp;Yunyi Ge,&nbsp;Bo Chen,&nbsp;Qiao Li,&nbsp;Gen Li,&nbsp;Yue Zhou,&nbsp;Jun Tian,&nbsp;Xiaofeng Liu,&nbsp;Zhichen Jing,&nbsp;Weiqun Gan,&nbsp;Kefei Song,&nbsp;Lingping He,&nbsp;Shijun Lei","doi":"10.1007/s11207-024-02310-1","DOIUrl":"10.1007/s11207-024-02310-1","url":null,"abstract":"<div><p>We present an automated solar flare detection software tool to automatically process solar observed images, detect and track solar flares, and finally compile an event catalog. It can identify and track flares that happen simultaneously or temporally close together. The method to identify a flare is based on the local intensity changes in macropixels. The basic characteristics, such as the time and location information of a flare, are determined with a triple-threshold scheme, with the first threshold (global threshold) to determine the occurrence (location) of the flare and the second and third thresholds (local thresholds) to determine the real start and end times of the flare. We have applied this tool to one month of continuous solar ultraviolet (UV) images obtained by the <i>Solar Disk Imager</i> (SDI) onboard the <i>Advanced Space-based Solar Observatory</i> (ASO-S), which show active phenomena such as flares, filaments or prominences, and solar jets. Our automated tool efficiently detected a total number of 226 solar events. After a visual inspection, we found that only one event was misidentified (unrelated to an active event). We compared the detected events with the GOES X-ray flare list and found that our tool can detect 81% of GOES M-class and above flares (29 out of 36), from which we conclude that the intensity increase in SDI UV images can be considered as a good indicator of a solar flare.</p></div>","PeriodicalId":777,"journal":{"name":"Solar Physics","volume":"299 5","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s11207-024-02310-1.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141167461","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":"Seismology of Curved Coronal Loops Using Multiperiodic Kink Oscillations","authors":"Igor Lopin","doi":"10.1007/s11207-024-02305-y","DOIUrl":"10.1007/s11207-024-02305-y","url":null,"abstract":"<div><p>It was shown recently that the model of a semicircular magnetic slab with oblique wave propagation and finite plasma-<span>(beta )</span> supports two fast surface modes, one of which produces vertical and the other horizontal kink-like motions. Their phase speeds (frequencies) depend upon the internal plasma-<span>(beta )</span> and slab aspect ratio. Thus the theory predicts the coexistence of two kink modes with different polarizations and periods in a single oscillating loop. In the present work, we aim to perform some analytical extensions of the developed theory and propose methods for seismological estimation of internal plasma-<span>(beta )</span> and internal Alfvén speed on the bases of multiperiodic kink oscillations of coronal loops. We show that when two fundamental modes of vertically and horizontally polarized kink oscillations with different periods are observed in a single coronal loop, this provides the seismological estimation of the internal plasma-<span>(beta )</span> and Alfvén speed. We also show that the combined effect of a finite plasma-<span>(beta )</span> and a slab curvature modifies the ratio of periods <span>(P_{1}/2P_{2})</span> of the fundamental mode and first overtone of a certain kink oscillation and the internal plasma-<span>(beta )</span> can be estimated using detected <span>(P_{1}/2P_{2})</span>. We also suggest that the strands with different temperatures that constitute the multithermal loops should oscillate with different periods and this may provide an estimate to the internal Alfvén speed in such loops. These findings are applied to a number of observations of multiperiodic coronal loop kink oscillations. Furthermore, a number of unusual observational results and the results of numerical simulations of kink oscillations in curved magnetic loops were interpreted on the bases of the developed theory.</p></div>","PeriodicalId":777,"journal":{"name":"Solar Physics","volume":"299 5","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141136374","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":"Machine Learning for Reconstruction of Polarity Inversion Lines from Solar Filaments","authors":"Vaclovas Kisielius,&nbsp;Egor Illarionov","doi":"10.1007/s11207-024-02324-9","DOIUrl":"10.1007/s11207-024-02324-9","url":null,"abstract":"<div><p>Solar filaments are well-known tracers of polarity inversion lines that separate two opposite magnetic polarities on the solar photosphere. Because observations of filaments began long before the systematic observations of solar magnetic fields, historical filament catalogs can facilitate the reconstruction of magnetic polarity maps at times when direct magnetic observations were not yet available. In practice, this reconstruction is often ambiguous and typically performed manually. We propose an automatic approach based on a machine-learning model that generates a variety of magnetic polarity maps consistent with filament observations. To evaluate the model and discuss the results, we use the catalog of solar filaments and polarity maps compiled by McIntosh. We realize that the process of manual compilation of polarity maps includes not only information on filaments, but also a large amount of prior information, which is difficult to formalize. To compensate for the lack of prior knowledge for the machine-learning model, we provide it with polarity information at several reference points. We demonstrate that this process, which can be considered as the user-guided reconstruction or superresolution, leads to polarity maps that are reasonably close to hand-drawn ones and additionally allows for uncertainty estimation.</p></div>","PeriodicalId":777,"journal":{"name":"Solar Physics","volume":"299 5","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141131314","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}