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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"

39320 results found.

  1. Fermi GRB 260115A: Global MASTER-Net observations report
  2. GRB 260115A: Fermi GBM Final Real-time Localization
  3. GRB 251222A: radio detection with the VLA
  4. GRB 260114A: VLT/HAWK-I near-infrared upper limits
  5. Konus-Wind detection of GRB 260114A
  6. GRB 260114A: Swift-XRT refined Analysis
  7. GRB 260114A: 6 GHz VLA observations
  8. GRB 260114A: VLT/X-shooter redshift of the putative host galaxy
  9. GRB 260114A : MITSuME Akeno optical upper limits
  10. GRB 260114A: COLIBRÍ optical upper limits
  11. GRB 260114A: TNG NIR upper limit
  12. GRB 260114A: NOT optical observations
  13. Konus-Wind detection of GRB 251230A / EP251230a
  14. GRB 260114A: SVOM/GRM observation of a short burst
  15. Swift GRB 260114A: Global MASTER-Net observations report
  16. GRB 260114A: GECAM-B observation of a short burst
  17. GRB 260114A: Mondy optical observations
  18. GRB 260114A: Fermi GBM observation
  19. GRB 260112B: GECAM-B observation
  20. GRB 260114A: GMG Optical Observation
  21. Fermi-LAT Gamma-ray Observations of IceCube-260111A
  22. GRB 260114A: Swift detection of a short burst
  23. GRB 260114A: Fermi GBM Final Real-time Localization
  24. EP-WXT trigger 01709251266: SVOM/C-GFT confirmation of a stellar flare
  25. Swift GRB260113.43: Global MASTER-Net observations report
  26. EP260110a: TRT optical upper limits
  27. Konus-Wind detection of GRB 260101A
  28. GRB 260111A: Swift-XRT observations
  29. Swift Trigger 1439093: is probably not GRB 260113A
  30. GRB 260111A: COLIBRÍ optical afterglow candidate
  31. GRB 260111A: GECAM-B observation of a burst
  32. GRB 260111A: Fermi GBM Observation
  33. Swift Trigger 1434591 is not a GRB
  34. GRB 260111A: GOTO optical upper limits
  35. GRB 260112B: Fermi GBM Final Real-time Localization
  36. GRB 260111A: Swift ToO observations
  37. GRB 251230A: Mondy Optical Observations
  38. GRB 260111A: Swift/BAT-GUANO arcminute localization of a burst
  39. GRB 260112A: Fermi GBM Final Real-time Localization
  40. IceCube-260111A - IceCube observation of a high-energy neutrino candidate track-like event
  41. IceCube Alert 260111A: Global MASTER-Net observations report
  42. EP260110a: Global MASTER-Net observations report
  43. Fermi GRB 260111A: Global MASTER-Net observations report
  44. GRB 260111A: Fermi GBM Final Real-time Localization
  45. EP260110a: KAIT optical upper limit
  46. EP 260110a: COLIBRÍ optical observations
  47. EP260110a: SVOM/C-GFT upper limit
  48. GRB 260109C: LCO optical upper limits
  49. GRB 260109C: Kilonova-Catcher optical upper limit
  50. EP260105b / GRB 260105C : Fermi-GBM Sub-Threshold Detection
  51. Swift Trigger 1434591: possible GRB 260109C
  52. GRB 260109B: Fermi GBM Final Real-time Localization
  53. GRB 260102A: Swift-XRT afterglow detection
  54. GRB 260109A: Fermi GBM Final Real-time Localization
  55. GRB 260104A: Swift-BAT refined analysis
  56. GRB 260101A: Swift-BAT refined analysis
  57. Swift GRB 251230A: Global MASTER-Net OT detection
  58. Fermi GRB 260107A: Global MASTER-Net observations report
  59. GRB 260102A: AbAO optical observations
  60. GRB 260107A: Fermi GBM Final Real-time Localization
  61. Fermi GRB 260105A: Global MASTER-Net observations report
  62. GRB 260105B: Fermi GBM Detection
  63. GRB 260105B: BALROG localization (Fermi Trigger 789348101 / GRB 260105973)
  64. GRB 260105A: SVOM/GRM observation
  65. GRB 260105B: SVOM/GRM observation
  66. FRB 20251229A: COLIBRÍ optical upper limits
  67. Fermi GRB 260105B: Global MASTER-Net observations report
  68. GRB 260105B: Fermi GBM Final Real-time Localization
  69. GRB 260105A: Fermi GBM Final Real-time Localization
  70. EP260104a: Global MASTER-Net observations report
  71. GRB 260101A: COLIBRÍ optical upper limits
  72. EP260105a: Global MASTER-Net observations report
  73. GRB 260103A: Insight-HXMT/HE detection
  74. GRB 260104A: COLIBRÍ optical upper limits
  75. GRB 260104C: Fermi GBM Final Real-time Localization
  76. Fermi GRB 260104B: Global MASTER-Net observations report
  77. Swift GRB 260104A: Global MASTER-Net observations report
  78. GRB 251230A/EP-WXT trigger 01709250693: Mephisto optical upper limits
  79. GRB 260104A: Swift-XRT refined Analysis
  80. GRB 260104A: Enhanced Swift-XRT position
  81. GRB 260101A: Swift/UVOT Detection
  82. GRB 260103A: GECAM-B observation of a burst
  83. GRB 260104B: Fermi GBM Final Localization
  84. GRB 260104A: Swift detection of a burst
  85. GRB 260103A: SVOM/GRM observation of a possible GRB
  86. GRB 260101A: COLIBRÍ optical observations
  87. SVOM GRB260103.08: Global MASTER-Net observations report
  88. GRB 260102B: Fermi GBM Final Real-time Localization
  89. SVOM GRB260102A: Global MASTER-Net observations report
  90. Fermi GBM Sub-Threshold Detection of GRB 260102A
  91. GRB 260102A: EP-FXT follow-up observation
  92. EP260101a: Global MASTER-Net observations report
  93. GRB 260102A: LCO optical upper limits
  94. GRB 260102A: Swift-XRT observations
  95. GRB 260102A: SVOM/COLIBRÍ (FM-GFT) optical observations
  96. Fermi Gamma-ray Burst Monitor trigger 789047602/260102495 is not a GRB
  97. GRB 251230A / EP251230a: GECAM-B detection
  98. GRB 260102A: SVOM/VT optical counterpart
  99. GRB 251230A / EP251230a: Insight-HXMT/HE detection
  100. GRB 260102A: Swift ToO observations

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