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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"

42952 results found.

  1. Konus-Wind detection of GRB 251230A / EP251230a
  2. GRB 260114A: SVOM/GRM observation of a short burst
  3. Swift GRB 260114A: Global MASTER-Net observations report
  4. GRB 260114A: GECAM-B observation of a short burst
  5. GRB 260114A: Mondy optical observations
  6. GRB 260114A: Fermi GBM observation
  7. GRB 260112B: GECAM-B observation
  8. GRB 260114A: GMG Optical Observation
  9. Fermi-LAT Gamma-ray Observations of IceCube-260111A
  10. GRB 260114A: Swift detection of a short burst
  11. GRB 260114A: Fermi GBM Final Real-time Localization
  12. EP-WXT trigger 01709251266: SVOM/C-GFT confirmation of a stellar flare
  13. IceCube-260111A: Upper limits from a search for additional neutrino events in IceCube
  14. Swift GRB260113.43: Global MASTER-Net observations report
  15. EP260110a: NOT and GTC Optical and Near-Infrared Observations
  16. EP260110a: TRT optical upper limits
  17. Konus-Wind detection of GRB 260101A
  18. GRB 260111A: Swift-XRT observations
  19. Swift Trigger 1439093: is probably not GRB 260113A
  20. GRB 260111A: COLIBRÍ optical afterglow candidate
  21. GRB 260111A: GECAM-B observation of a burst
  22. GRB 260111A: Fermi GBM Observation
  23. The EP-WXT trigger 01709251266 is likely a flaring star
  24. GRB 260111A: GOTO optical upper limits
  25. GRB 260112B: Fermi GBM Final Real-time Localization
  26. GRB 260111A: Swift ToO observations
  27. GRB 251230A: Mondy Optical Observations
  28. GRB 260111A: Swift/BAT-GUANO arcminute localization of a burst
  29. GRB 260112A: Fermi GBM Final Real-time Localization
  30. EP260110a: SVOM/VT optical upper limits
  31. IceCube-260111A - IceCube observation of a high-energy neutrino candidate track-like event
  32. IceCube Alert 260111A: Global MASTER-Net observations report
  33. EP260110a: Global MASTER-Net observations report
  34. Fermi GRB 260111A: Global MASTER-Net observations report
  35. GRB 260111A: Fermi GBM Final Real-time Localization
  36. Swift trigger 1436759 is not an astrophysical event
  37. EP260110a: KAIT optical upper limit
  38. EP260110a: refined analysis of the EP-WXT and EP-FXT observations
  39. EP 260110a: COLIBRÍ optical observations
  40. EP260110a: SVOM/C-GFT upper limit
  41. EP260110a: BOOTES-5/JGU optical upper limit
  42. EP260110a: Einstein Probe detection of an X-ray transient
  43. GRB 260109C: LCO optical upper limits
  44. GRB 260109C: Kilonova-Catcher optical upper limit
  45. EP260105b / GRB 260105C : Fermi-GBM Sub-Threshold Detection
  46. Swift Trigger 1434591: possible GRB 260109C
  47. GRB 260109B: Fermi GBM Final Real-time Localization
  48. GRB 260102A: Swift-XRT afterglow detection
  49. GRB 260109A: Fermi GBM Final Real-time Localization
  50. GRB 260104A: Swift-BAT refined analysis
  51. GRB 260101A: Swift-BAT refined analysis
  52. Swift GRB 251230A: Global MASTER-Net OT detection
  53. Fermi GRB 260107A: Global MASTER-Net observations report
  54. GRB 260102A: AbAO optical observations
  55. GRB 260107A: Fermi GBM Final Real-time Localization
  56. EP260105b/EP-WXT trigger 01709251028: Einstein Probe detection of an X-ray transient
  57. The EP-WXT trigger 01709251112 is likely a flaring star
  58. Fermi GRB 260105A: Global MASTER-Net observations report
  59. GRB 260105B: Fermi GBM Detection
  60. EP260105a: FTW optical observations
  61. EP260104a: FTW optical observations
  62. GRB 260105B: BALROG localization (Fermi Trigger 789348101 / GRB 260105973)
  63. GRB 260105A: SVOM/GRM observation
  64. GRB 260105B: SVOM/GRM observation
  65. The EP-WXT trigger 01709251028 is likely a flaring star
  66. FRB 20251229A: COLIBRÍ optical upper limits
  67. Fermi GRB 260105B: Global MASTER-Net observations report
  68. EP260105a: SVOM/VT optical upperlimit
  69. GRB 260105B: Fermi GBM Final Real-time Localization
  70. GRB 260105A: Fermi GBM Final Real-time Localization
  71. FRB 20251229A: A potentially hyperactive repeating fast radio burst source
  72. EP260105a: refined analysis of the EP-WXT and EP-FXT observations
  73. EP260105a: LCO Optical Upper limit
  74. EP260104a: Global MASTER-Net observations report
  75. EP260104a: Einstein Probe detection of a fast X-ray transient
  76. GRB 260101A: COLIBRÍ optical upper limits
  77. EP260105a: Global MASTER-Net observations report
  78. EP260105a: Einstein Probe detection of an X-ray transient
  79. GRB 260103A: Insight-HXMT/HE detection
  80. GRB 260104A: COLIBRÍ optical upper limits
  81. GRB 260104C: Fermi GBM Final Real-time Localization
  82. Fermi GRB 260104B: Global MASTER-Net observations report
  83. Swift GRB 260104A: Global MASTER-Net observations report
  84. GRB 251230A/EP-WXT trigger 01709250693: Mephisto optical upper limits
  85. GRB 260104A: Swift-XRT refined Analysis
  86. GRB 260104A: Enhanced Swift-XRT position
  87. GRB 260101A: Swift/UVOT Detection
  88. GRB 260103A: GECAM-B observation of a burst
  89. GRB 260104B: Fermi GBM Final Localization
  90. GRB 260104A: Swift detection of a burst
  91. GRB 260103A: SVOM/GRM observation of a possible GRB
  92. Fermi-LAT Gamma-ray Observations of IceCube-251225A
  93. GRB 260101A: COLIBRÍ optical observations
  94. SVOM GRB260103.08: Global MASTER-Net observations report
  95. GRB 260102B: Fermi GBM Final Real-time Localization
  96. SVOM GRB260102A: Global MASTER-Net observations report
  97. Fermi GBM Sub-Threshold Detection of GRB 260102A
  98. GRB 260102A: EP-FXT follow-up observation
  99. EP260101a: Global MASTER-Net observations report
  100. GRB 260102A: LCO optical upper limits

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