Abstract
The post-flare loop is a typical dynamic process of solar flares. In the past, a manual method was used to recognize the strand structure of loops. With higher spatial resolving power, the post-flare loop consists of more bundles of strands. For fast and reliable post-flare-loop recognition, an automated post-flare-loop detection method applied to high-resolution H\(\upalpha \) red-wing images is proposed in this article. In this method, straight lines are detected from the edge-detection result, and then a curve-growing procedure is carried out on the basis of the detected straight lines. Finally, the grown curves are screened to eliminate isolated and intersected curves. To our knowledge, our research is the first trial to detect post-flare loops on the solar disk. Experimental results with the high-resolution H\(\upalpha \) red-wing images from the Goode Solar Telescope (GST) have verified that the proposed method could detect post-flare loops effectively in all their developing phases. Based on the recognition results, the automatically computed loop widths (118±35 km) are consistent with the manually derived results (124±19 km). With the development of observing instrumentation, the proposed method may recognize each strand of the loops and the measured loop widths could be used to verify flare models.
Similar content being viewed by others
Code Availability
The code of the proposed method has been published on github: github.com/PostFlareLoop/postflareloop.
References
Adams, R., Bischof, L.: 1994, Seeded region growing. IEEE Trans. Pattern Anal. Mach. Intell. 16, 641. DOI.
Antolin, P., Rouppe van der Voort, L.: 2012, Observing the fine structure of loops through high resolution spectroscopic observations of coronal rain with the CRISP instrument at the Swedish Solar Telescope. Astrophys. J. 745, 152. DOI. ADS.
Aschwanden, M.J.: 2010, A code for automated tracing of coronal loops approaching visual perception. Solar Phys. 262, 399. DOI. ADS.
Bruzek, A.: 1964, On the association between loop prominences and flares. Astrophys. J. 140, 746. DOI. ADS.
Cao, W., Gorceix, N., Coulter, R., Ahn, K., Rimmele, T.R., Goode, P.R.: 2010, Scientific instrumentation for the 1.6 m New Solar Telescope in Big Bear. Astron. Nachr. 331, 636. DOI. ADS.
Cargill, P.J.: 1994, Some implications of the nanoflare concept. Astrophys. J. 422, 381. DOI. ADS.
Cargill, P.J., Klimchuk, J.A.: 2004, Nanoflare heating of the corona revisited. Astrophys. J. 605, 911. DOI. ADS.
Cheng, X., Ding, M.D., Guo, Y., Zhang, J., Jing, J., Wiegelmann, T.: 2010, Re-flaring of a post-flare loop system driven by flux rope emergence and twisting. Astrophys. J. Lett. 716, L68. DOI. ADS.
Denker, C., Johannesson, A., Marquette, W., Goode, P.R., Wang, H., Zirin, H.: 1999, Synoptic H\(\upalpha \) full-disk observations of the Sun from Big Bear Solar Observatory – I. Instrumentation, image processing, data products, and first results. Solar Phys. 184, 87. DOI. ADS.
Duda, R.O., Hart, P.E.: 1972, Use of the Hough transformation to detect lines and curves in pictures. Commun. ACM 15, 11. DOI.
Durak, N., Nasraoui, O., Schmelz, J.: 2009, Coronal loop detection from solar images. Pattern Recognit. 42, 2481. DOI.
Forbes, T.G., Malherbe, J.M., Priest, E.R.: 1989, The formation of flare loops by magnetic reconnection and chromospheric ablation. Solar Phys. 120, 285. DOI. ADS.
Grigorescu, C., Petkov, N., Westenberg, M.A.: 2003, Contour detection based on nonclassical receptive field inhibition. IEEE Trans. Image Process. 12, 729.
Heinzel, P., Karlický, M.: 1987, H\(\upalpha \) diagnostics of (post)-flare loops based on narrow-band filtergram observations. Solar Phys. 110, 343. DOI. ADS.
Inhester, B., Feng, L., Wiegelmann, T.: 2008, Segmentation of loops from coronal EUV images. Solar Phys. 248, 379. DOI. ADS.
Jing, J., Xu, Y., Cao, W., Liu, C., Gary, D., Wang, H.: 2016, Unprecedented fine structure of a solar flare revealed by the 1.6 m New Solar Telescope. Sci. Rep. 6, 24319. DOI. ADS.
Kamio, S., Kurokawa, H., Ishii, T.T.: 2003, Precise determination of cooling times of post-flare loops from the detailed comparison between H\(\upalpha \) and soft X-ray images. Solar Phys. 215, 127. DOI. ADS.
Klimchuk, J.A.: 2006, On solving the coronal heating problem. Solar Phys. 234, 41. DOI. ADS.
Lin, J., Zhang, Z., Wang, Z., Smartt, R.N.: 1992, The morphological characteristics and cooling mechanisms of the post-flare loop system of April 28, 1980. Astron. Astrophys. 253, 557. ADS.
McAteer, R.T.J., Kestener, P., Arneodo, A., Khalil, A.: 2010, Segmentation of loops from coronal EUV images. Solar Phys. 262, 387. DOI. ADS.
Podgorny, A.I., Podgorny, I.M.: 2002, Numerical MHD simulations of post-flare loop formation on the Sun allowing for thermal-conductivity anisotropy. Astron. Rep. 46, 67. DOI. ADS.
Reeves, K.K., Warren, H.P.: 2002, Modeling the cooling of postflare loops. Astrophys. J. 578, 590. DOI. ADS.
Rimmele, T.R., Warner, M., Keil, S.L., Goode, P.R., Knölker, M., Kuhn, J.R., Rosner, R.R., McMullin, J.P., Casini, R., Lin, H., Wöger, F., von der Lühe, O., Tritschler, A., Davey, A., de Wijn, A., Elmore, D.F., Fehlmann, A., Harrington, D.M., Jaeggli, S.A., Rast, M.P., Schad, T.A., Schmidt, W., Mathioudakis, M., Mickey, D.L., Anan, T., Beck, C., Marshall, H.K., Jeffers, P.F., Oschmann, J.M., Beard, A., Berst, D.C., Cowan, B.A., Craig, S.C., Cross, E., Cummings, B.K., Donnelly, C., de Vanssay, J.-B., Eigenbrot, A.D., Ferayorni, A., Foster, C., Galapon, C.A., Gedrites, C., Gonzales, K., Goodrich, B.D., Gregory, B.S., Guzman, S.S., Guzzo, S., Hegwer, S., Hubbard, R.P., Hubbard, J.R., Johansson, E.M., Johnson, L.C., Liang, C., Liang, M., McQuillen, I., Mayer, C., Newman, K., Onodera, B., Phelps, L., Puentes, M.M., Richards, C., Rimmele, L.M., Sekulic, P., Shimko, S.R., Simison, B.E., Smith, B., Starman, E., Sueoka, S.R., Summers, R.T., Szabo, A., Szabo, L., Wampler, S.B., Williams, T.R., White, C.: 2020, The Daniel K. Inouye Solar Telescope – observatory overview. Solar Phys. 295, 172. DOI. ADS.
Sakamoto, Y., Tsuneta, S., Vekstein, G.: 2008, Observational appearance of nanoflares with SXT and TRACE. Astrophys. J. 689, 1421. DOI. ADS.
Samet, H., Tamminen, M.: 1988, Efficient component labeling of images of arbitrary dimension represented by linear bintrees. IEEE Trans. Pattern Anal. Mach. Intell. 10, 579. DOI.
Scharmer, G.B., Narayan, G., Hillberg, T., de la Cruz Rodriguez, J., Löfdahl, M.G., Kiselman, D., Sütterlin, P., van Noort, M., Lagg, A.: 2008, CRISP spectropolarimetric imaging of penumbral fine structure. Astrophys. J. Lett. 689, L69. DOI. ADS.
Scullion, E., Rouppe van der Voort, L., Wedemeyer, S., Antolin, P.: 2014, Unresolved fine-scale structure in solar coronal loop-tops. Astrophys. J. 797, 36. DOI. ADS.
Sellah, S., Nasraoui, O.: 2008, An incremental Hough transform for detecting ellipse in image data streams. In: 20th IEEE International Conference on Tools with Artificial Intelligence 2, 45. DOI.
Solanki, S.K.: 2003, Sunspots: an overview. Astron. Astrophys. Rev. 11, 153. DOI. ADS.
Srivastava, A.K., Zaqarashvili, T.V., Uddin, W., Dwivedi, B.N., Kumar, P.: 2008, Observation of multiple sausage oscillations in cool post-flare loop. Mon. Not. Roy. Astron. Soc. 388, 1899. DOI. ADS.
Vekstein, G.: 2009, Probing nanoflares with observed fluctuations of the coronal EUV emission. Astron. Astrophys. 499, L5. DOI. ADS.
White, R.S., Verwichte, E., Foullon, C.: 2012, First observation of a transverse vertical oscillation during the formation of a hot post-flare loop. Astron. Astrophys. 545, A129. DOI. ADS.
Yang, M., Tian, Y., Liu, Y., Rao, C.: 2018, Automated solar flare detection and feature extraction in high-resolution and full-disk H\(\upalpha \) images. Solar Phys. 293, 81. DOI. ADS.
Acknowledgment
We gratefully acknowledge the use of data from the Goode Solar Telescope (GST) of the Big Bear Solar Observatory (BBSO). BBSO operation is supported by NJIT and US NSF AGS-1821294 grant. GST operation is partly supported by the Korea Astronomy and Space Science Institute and the Seoul National University.
Funding
This work was supported by Natural National Science Foundation of China (NO.11727805 and NO.11703029) and the Laboratory Innovation Foundation of the Chinese Academy of Sciences (Grant NO. YJ16K006).
Author information
Authors and Affiliations
Contributions
Meng Yang and Xiaoying Gong contributed equally to this work. They completed the writing, experimentation, and revision of the article. Yangyi Liu and Yu Tian collected data and made suggestions on the method of the article. Changhui Rao supervised this work.
Corresponding author
Ethics declarations
Disclosure of Potential Conflicts of Interest
The authors declare that they have no conflicts of interest.
Additional information
Publisher’s Note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Rights and permissions
About this article
Cite this article
Yang, M., Gong, X., Liu, Y. et al. Automated Recognition of Post-Flare Loops in High-Resolution H\(\upalpha \) Red-Wing Images. Sol Phys 297, 62 (2022). https://doi.org/10.1007/s11207-022-01993-8
Received:
Accepted:
Published:
DOI: https://doi.org/10.1007/s11207-022-01993-8