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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"

39297 results found.

  1. GRB 260213A: GECAM-B observation of a short burst
  2. GRB 260216A: Fermi Gamma-ray Burst Monitor trigger 792969362/260216886 is not a GRB
  3. GRB 260216A: Fermi GBM Final Real-time Localization
  4. GRB 260206A: probable hard X-ray burst from 4U 0513-40
  5. EP260214a: Optical upper limits with Kinder observations
  6. EP260214a / GRB 260214A: Fermi-GBM Sub-Threshold Detection
  7. EP260214b: GROWTH-India Telescope optical upper limit
  8. EP260214a: COLIBRÍ optical upper limits
  9. EP260214b: LCO optical counterpart detection
  10. EP260214b: VLT/X-shooter spectroscopic redshift z = 1.208
  11. GRB 260211A: SVOM/VT optical counterpart
  12. EP260214b: COLIBRÍ optical observations
  13. EP260214a: Global MASTER-Net observations report
  14. GRB 260212A: AstroSat CZTI detection
  15. GRB 260212A: Fermi GBM Observation
  16. EP260213a: Global MASTER-Net observations report
  17. EP260213a: COLIBRÍ optical upper limits
  18. GRB 260212A: GECAM-B observation
  19. EP260213a: Mondy R-band optical upper limit
  20. EP260213a: SVOM/C-GFT upper limit
  21. GRB 260212A: SVOM/GRM observation of a long burst
  22. GRB 260213B: Fermi GBM Final Localization
  23. GRB 260213B: BALROG localization (Fermi Trigger 792697214 / GRB 260213736)
  24. GRB 260211A - SVOM/ECLAIRs refined analysis
  25. GRB 260204A: SVOM/ECLAIRs refined analysis
  26. GRB 260213A: Fermi GBM Final Localization
  27. GRB 260211A: EP-FXT follow-up observation
  28. GRB 260211A: SVOM/VT optical observation
  29. GRB 260212A: Glowbug gamma-ray detection
  30. GRB 260211A: GOTO optical upper limit
  31. Fermi GRB 260212A: Global MASTER-Net observations report
  32. GRB 260212A: Fermi GBM Final Real-time Localization
  33. GRB 260211A: LAST optical upper limit
  34. GRB 260210A: SVOM/GRM observation
  35. Fermi GBM Sub-Threshold Detection of GRB 260211A
  36. Konus-Wind detection of GRB 260207B
  37. GRB 260128B: SVOM/ECLAIRs refined analysis
  38. GRID detection of GRB 260207B
  39. GRB 260211A: LCO optical upper limits
  40. GRB260131A/B: 3.6m DOT Optical Observations
  41. GRB 260211A: SVOM/COLIBRÍ (FM-GFT) optical upper limits
  42. Fermi trigger No 792537871: Global MASTER-Net observations report
  43. GRB 260211A: SVOM detection of a burst
  44. Konus-Wind detection of GRB 260209B
  45. GRB 260208A: Swift UVOT detection
  46. Konus-Wind detection of GRB 260127B
  47. EP260209a: COLIBRÍ optical upper limit
  48. Fermi GRB 260210C: Global MASTER-Net observations report
  49. EP260209a: LCO optical upper limits
  50. EP260210a: Global MASTER-Net observations report
  51. EP260209a: Global MASTER-Net observations report
  52. GRB 260208A: LCO detection of the optical counterpart
  53. IPN triangulation of GRB 260207B (short/hard with EE)
  54. GRB 260210C: Fermi GBM Final Real-time Localization
  55. GRB 260210A: Glowbug gamma-ray detection
  56. GRB 260210B: Fermi GBM Final Real-time Localization
  57. GRB 260210A: AstroSat CZTI detection
  58. GRB 260208C: AstroSat CZTI detection
  59. EP260210a: COLIBRÍ optical upper limit
  60. EP260210a: SVOM/C-GFT upper limit
  61. GRB 260208B: refined analysis of the EP-FXT observation
  62. GRB 260207B: AstroSat CZTI detection
  63. GRB 260208C: SVOM/GRM observation
  64. GRB 260204A: Swift-XRT afterglow detection
  65. GRB 260208B: AstroSat CZTI detection of a bright long burst
  66. GRB 260208A: Glowbug gamma-ray detection
  67. GRB 260208A: NuSTAR detection of prompt emission
  68. GRB 260208A: Fermi GBM Observation
  69. Fermi GRB 260209A: Global MASTER-Net observations report
  70. GRB 260208B: Swift-XRT observations
  71. GRB 260131A/B: continued Mondy optical observations
  72. GRB 260204A: Swift/UVOT Upper Limits
  73. GRB 260208B: COLIBRÍ optical observations
  74. GRB 260208A: Mondy optical observations (duplicate submission)
  75. GRB 260208A: Mondy optical observations
  76. GRB 260208A: 1.3m DFOT optical detection
  77. GRB 260208A: COLIBRÍ optical observations
  78. GRB 260208B: EP-FXT observation
  79. GRB 260208A: NOT spectroscopic redshift z = 2.36
  80. GRB 260208A: Liverpool Telescope optical detection
  81. Fermi GRB 260208C: Global MASTER-Net observations report
  82. GRB 260208B: SVOM/VT optical candidate
  83. GRB 260208A: GECAM-B observation of a bright burst
  84. GRB 260208A: Zwicky Transient Facility Follow-Up of a Fermi GRB (Trigger 792220053)
  85. GRB 260209A: Fermi GBM Final Real-time Localization
  86. GRB 260208A: SVOM/VT optical observation
  87. Fermi GRB 260208D: Global MASTER-Net observations report
  88. GRB 260208D: Fermi GBM Final Real-time Localization
  89. GRB 260208A: Swift-XRT observations
  90. GRB 260208B: Swift ToO observations
  91. GRB 260208B: SVOM/GRM observation of a bright burst
  92. GRB 260208B: Fermi GBM Detection
  93. LAT GRB 260208B: Global MASTER-Net observations report
  94. GRB 260208B: Fermi-LAT detection
  95. GRB 260208C: Fermi GBM Final Real-time Localization
  96. GRB 260208A: Fermi-LAT detection
  97. GRB 260207B: GECAM-B observation
  98. GRB 260208A: Swift ToO observations
  99. GRB 260208A: Fermi GBM Classification Correction
  100. GRB 260208A: GOTO detection of a potential optical counterpart (GOTO26aob)

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