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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"

36193 results found.

  1. GRB 260226A: AstroSat CZTI detection of bright long burst
  2. GRB 260226A: Fermi-LAT detection of a bright burst
  3. GRB 260226A???: BALROG localization (Fermi Trigger 793795080 / GRB 260226443)
  4. GRB260225A: SVOM/ECLAIRs refined position
  5. GRB 260226A: Fermi GBM Final Real-time Localization
  6. GRB 260225A: EP-FXT follow-up observation
  7. GRB 260225A: SVOM/VT optical observation
  8. GRB 260225A: SVOM/COLIBRÍ (FM-GFT) Detection of an Optical Counterpart Candidate
  9. GRB 260225C: Fermi GBM Final Real-time Localization
  10. GRB 260223A: Fermi GBM Observation
  11. GRB 260225A: SVOM/VT optical upper limits
  12. GRB 260225B: Fermi GBM Final Real-time Localization
  13. GRB 260225A: SVOM/COLIBRÍ (FM-GFT) optical upper limits
  14. GRB 260225A: SVOM detection of a burst
  15. GRB 260223A: Glowbug gamma-ray detection
  16. GRB 260223A: COLIBRÍ optical afterglow decay confirmation
  17. GRB 260223A: SVOM/VT optical observation
  18. GRB 260223A: SVOM/GRM observation
  19. GRB 260223A: COLIBRÍ further optical observations and a brightening
  20. GRB 260223A: COLIBRÍ optical observations
  21. GRB 260223A: DDOTI Optical Candidate
  22. GRB 260223A: BALROG localization (Fermi Trigger 793512674 / GRB 260223174)
  23. Fermi GRB 260223A: Global MASTER-Net observations report
  24. GRB 260223A: Fermi GBM Final Real-time Localization
  25. GRB 260222A: Fermi GBM Final Real-time Localization
  26. Fermi GRB 260221B: Global MASTER-Net observations report
  27. GRB 260221B: Fermi GBM Final Real-time Localization
  28. Fermi GRB 260221A: Global MASTER-Net observations report
  29. GRB 260221A: Fermi GBM Final Real-time Localization
  30. GRB 260219A: AstroSat CZTI detection
  31. IceCube-260217A: Upper limits from a search for additional neutrino events in IceCube
  32. GRB 260219A: GECAM-B observation of a long burst
  33. Fermi GRB 260219A: Global MASTER-Net observations report
  34. GRB 260219A: Fermi GBM Final Real-time Localization
  35. GRB 260217A: Fermi GBM Final Localization
  36. GRB 260214B/EP260214b: SVOM/ECLAIRs detection through targeted search
  37. EP260214b: Mondy optical observations
  38. EP260210a: Mondy optical upper limits
  39. Konus-Wind detection of GRB 260212A
  40. GRB 260208A: AbAO and Terskol optical upper limits
  41. GRB 260208A: continued Mondy optical observations
  42. IPN triangulation of GRB 260212A
  43. GRB 260213A: GECAM-B observation of a short burst
  44. GRB 260216A: Fermi Gamma-ray Burst Monitor trigger 792969362/260216886 is not a GRB
  45. GRB 260216A: Fermi GBM Final Real-time Localization
  46. GRB 260206A: probable hard X-ray burst from 4U 0513-40
  47. EP260214a: Optical upper limits with Kinder observations
  48. EP260214a / GRB 260214A: Fermi-GBM Sub-Threshold Detection
  49. EP260214b: VLT/X-shooter spectroscopic redshift z = 1.208
  50. GRB 260211A: SVOM/VT optical counterpart
  51. GRB 260212A: AstroSat CZTI detection
  52. GRB 260212A: Fermi GBM Observation
  53. GRB 260212A: GECAM-B observation
  54. EP260213a: Mondy R-band optical upper limit
  55. GRB 260212A: SVOM/GRM observation of a long burst
  56. GRB 260213B: Fermi GBM Final Localization
  57. GRB 260213B: BALROG localization (Fermi Trigger 792697214 / GRB 260213736)
  58. GRB 260211A - SVOM/ECLAIRs refined analysis
  59. GRB 260204A: SVOM/ECLAIRs refined analysis
  60. GRB 260213A: Fermi GBM Final Localization
  61. GRB 260211A: EP-FXT follow-up observation
  62. GRB 260211A: SVOM/VT optical observation
  63. GRB 260212A: Glowbug gamma-ray detection
  64. GRB 260211A: GOTO optical upper limit
  65. Fermi GRB 260212A: Global MASTER-Net observations report
  66. GRB 260212A: Fermi GBM Final Real-time Localization
  67. GRB 260211A: LAST optical upper limit
  68. GRB 260210A: SVOM/GRM observation
  69. Fermi GBM Sub-Threshold Detection of GRB 260211A
  70. Konus-Wind detection of GRB 260207B
  71. GRB 260128B: SVOM/ECLAIRs refined analysis
  72. GRID detection of GRB 260207B
  73. GRB 260211A: LCO optical upper limits
  74. GRB260131A/B: 3.6m DOT Optical Observations
  75. GRB 260211A: SVOM/COLIBRÍ (FM-GFT) optical upper limits
  76. GRB 260211A: SVOM detection of a burst
  77. Konus-Wind detection of GRB 260209B
  78. GRB 260208A: Swift UVOT detection
  79. Konus-Wind detection of GRB 260127B
  80. Fermi GRB 260210C: Global MASTER-Net observations report
  81. GRB 260208A: LCO detection of the optical counterpart
  82. IPN triangulation of GRB 260207B (short/hard with EE)
  83. GRB 260210C: Fermi GBM Final Real-time Localization
  84. GRB 260210A: Glowbug gamma-ray detection
  85. GRB 260210B: Fermi GBM Final Real-time Localization
  86. GRB 260210A: AstroSat CZTI detection
  87. GRB 260208C: AstroSat CZTI detection
  88. GRB 260208B: refined analysis of the EP-FXT observation
  89. GRB 260207B: AstroSat CZTI detection
  90. GRB 260208C: SVOM/GRM observation
  91. GRB 260204A: Swift-XRT afterglow detection
  92. GRB 260208B: AstroSat CZTI detection of a bright long burst
  93. GRB 260208A: Glowbug gamma-ray detection
  94. GRB 260208A: NuSTAR detection of prompt emission
  95. GRB 260208A: Fermi GBM Observation
  96. Fermi GRB 260209A: Global MASTER-Net observations report
  97. GRB 260208B: Swift-XRT observations
  98. GRB 260131A/B: continued Mondy optical observations
  99. GRB 260204A: Swift/UVOT Upper Limits
  100. GRB 260208B: COLIBRÍ optical observations

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