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GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. See the documentation for help with subscribing to or submitting Circulars.

Search for Circulars by submitter, subject, or body text (e.g. 'Fermi GRB').
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
Advanced Search

To narrow the search results, use advanced search syntax. This allows for specifying which circular field to search (submitter, subject, and/or body). For additional information, refer to the advanced search documentation.

Advanced Search Examples (click to copy):

subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

36147 results found.

  1. GRB 260225D: Glowbug gamma-ray detection of a likely short burst
  2. GRB 260226A: Glowbug gamma-ray detection
  3. GRB 260226A: NuSTAR detection of bright prompt emission
  4. GRB 260226A : GROWTH-India Telescope optical observations
  5. GRB 260226A: LAST optical upper limit
  6. GRB 260226A: Fermi GBM observation
  7. GRB 260226A: Fermi-LAT refined analysis
  8. Fermi GRB 260226A: Global MASTER-Net observations report
  9. GRB 260226A: AstroSat CZTI detection of bright long burst
  10. GRB 260226A: Fermi-LAT detection of a bright burst
  11. GRB 260226A???: BALROG localization (Fermi Trigger 793795080 / GRB 260226443)
  12. GRB260225A: SVOM/ECLAIRs refined position
  13. GRB 260226A: Fermi GBM Final Real-time Localization
  14. GRB 260225A: EP-FXT follow-up observation
  15. GRB 260225A: SVOM/VT optical observation
  16. GRB 260225A: SVOM/COLIBRÍ (FM-GFT) Detection of an Optical Counterpart Candidate
  17. GRB 260225C: Fermi GBM Final Real-time Localization
  18. GRB 260223A: Fermi GBM Observation
  19. GRB 260225A: SVOM/VT optical upper limits
  20. GRB 260225B: Fermi GBM Final Real-time Localization
  21. GRB 260225A: SVOM/COLIBRÍ (FM-GFT) optical upper limits
  22. GRB 260225A: SVOM detection of a burst
  23. GRB 260223A: Glowbug gamma-ray detection
  24. GRB 260223A: COLIBRÍ optical afterglow decay confirmation
  25. GRB 260223A: SVOM/VT optical observation
  26. GRB 260223A: SVOM/GRM observation
  27. GRB 260223A: COLIBRÍ further optical observations and a brightening
  28. GRB 260223A: COLIBRÍ optical observations
  29. GRB 260223A: DDOTI Optical Candidate
  30. GRB 260223A: BALROG localization (Fermi Trigger 793512674 / GRB 260223174)
  31. Fermi GRB 260223A: Global MASTER-Net observations report
  32. GRB 260223A: Fermi GBM Final Real-time Localization
  33. GRB 260222A: Fermi GBM Final Real-time Localization
  34. Fermi GRB 260221B: Global MASTER-Net observations report
  35. GRB 260221B: Fermi GBM Final Real-time Localization
  36. Fermi GRB 260221A: Global MASTER-Net observations report
  37. GRB 260221A: Fermi GBM Final Real-time Localization
  38. GRB 260219A: AstroSat CZTI detection
  39. GRB 260219A: GECAM-B observation of a long burst
  40. Fermi GRB 260219A: Global MASTER-Net observations report
  41. GRB 260219A: Fermi GBM Final Real-time Localization
  42. GRB 260217A: Fermi GBM Final Localization
  43. GRB 260214B/EP260214b: SVOM/ECLAIRs detection through targeted search
  44. EP260214b: Mondy optical observations
  45. EP260210a: Mondy optical upper limits
  46. Konus-Wind detection of GRB 260212A
  47. GRB 260208A: AbAO and Terskol optical upper limits
  48. GRB 260208A: continued Mondy optical observations
  49. IPN triangulation of GRB 260212A
  50. GRB 260213A: GECAM-B observation of a short burst
  51. GRB 260216A: Fermi Gamma-ray Burst Monitor trigger 792969362/260216886 is not a GRB
  52. GRB 260216A: Fermi GBM Final Real-time Localization
  53. GRB 260206A: probable hard X-ray burst from 4U 0513-40
  54. EP260214a: Optical upper limits with Kinder observations
  55. EP260214a / GRB 260214A: Fermi-GBM Sub-Threshold Detection
  56. EP260214b: VLT/X-shooter spectroscopic redshift z = 1.208
  57. GRB 260211A: SVOM/VT optical counterpart
  58. GRB 260212A: AstroSat CZTI detection
  59. GRB 260212A: Fermi GBM Observation
  60. GRB 260212A: GECAM-B observation
  61. EP260213a: Mondy R-band optical upper limit
  62. GRB 260212A: SVOM/GRM observation of a long burst
  63. GRB 260213B: Fermi GBM Final Localization
  64. GRB 260213B: BALROG localization (Fermi Trigger 792697214 / GRB 260213736)
  65. GRB 260211A - SVOM/ECLAIRs refined analysis
  66. GRB 260204A: SVOM/ECLAIRs refined analysis
  67. GRB 260213A: Fermi GBM Final Localization
  68. GRB 260211A: EP-FXT follow-up observation
  69. GRB 260211A: SVOM/VT optical observation
  70. GRB 260212A: Glowbug gamma-ray detection
  71. GRB 260211A: GOTO optical upper limit
  72. Fermi GRB 260212A: Global MASTER-Net observations report
  73. GRB 260212A: Fermi GBM Final Real-time Localization
  74. GRB 260211A: LAST optical upper limit
  75. GRB 260210A: SVOM/GRM observation
  76. Fermi GBM Sub-Threshold Detection of GRB 260211A
  77. Konus-Wind detection of GRB 260207B
  78. GRB 260128B: SVOM/ECLAIRs refined analysis
  79. GRID detection of GRB 260207B
  80. GRB 260211A: LCO optical upper limits
  81. GRB260131A/B: 3.6m DOT Optical Observations
  82. GRB 260211A: SVOM/COLIBRÍ (FM-GFT) optical upper limits
  83. GRB 260211A: SVOM detection of a burst
  84. Konus-Wind detection of GRB 260209B
  85. GRB 260208A: Swift UVOT detection
  86. Konus-Wind detection of GRB 260127B
  87. Fermi GRB 260210C: Global MASTER-Net observations report
  88. GRB 260208A: LCO detection of the optical counterpart
  89. IPN triangulation of GRB 260207B (short/hard with EE)
  90. GRB 260210C: Fermi GBM Final Real-time Localization
  91. GRB 260210A: Glowbug gamma-ray detection
  92. GRB 260210B: Fermi GBM Final Real-time Localization
  93. GRB 260210A: AstroSat CZTI detection
  94. GRB 260208C: AstroSat CZTI detection
  95. GRB 260208B: refined analysis of the EP-FXT observation
  96. GRB 260207B: AstroSat CZTI detection
  97. GRB 260208C: SVOM/GRM observation
  98. GRB 260204A: Swift-XRT afterglow detection
  99. GRB 260208B: AstroSat CZTI detection of a bright long burst
  100. GRB 260208A: Glowbug gamma-ray detection

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