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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"

45893 results found.

  1. GRB 251222A: radio detection with the VLA
  2. GRB 260114A: VLT/HAWK-I near-infrared upper limits
  3. Konus-Wind detection of GRB 260114A
  4. GRB 260114A: Swift-XRT refined Analysis
  5. GRB 260114A: 6 GHz VLA observations
  6. GRB 260114A: VLT/X-shooter redshift of the putative host galaxy
  7. GRB 260114A : MITSuME Akeno optical upper limits
  8. GRB 260114A: COLIBRÍ optical upper limits
  9. GRB 260114A: TNG NIR upper limit
  10. GRB 260114A: NOT optical observations
  11. Konus-Wind detection of GRB 251230A / EP251230a
  12. GRB 260114A: SVOM/GRM observation of a short burst
  13. Swift GRB 260114A: Global MASTER-Net observations report
  14. GRB 260114A: GECAM-B observation of a short burst
  15. GRB 260114A: Mondy optical observations
  16. GRB 260114A: Fermi GBM observation
  17. GRB 260112B: GECAM-B observation
  18. GRB 260114A: GMG Optical Observation
  19. Fermi-LAT Gamma-ray Observations of IceCube-260111A
  20. GRB 260114A: Swift detection of a short burst
  21. GRB 260114A: Fermi GBM Final Real-time Localization
  22. EP-WXT trigger 01709251266: SVOM/C-GFT confirmation of a stellar flare
  23. IceCube-260111A: Upper limits from a search for additional neutrino events in IceCube
  24. Swift GRB260113.43: Global MASTER-Net observations report
  25. EP260110a: NOT and GTC Optical and Near-Infrared Observations
  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. The EP-WXT trigger 01709251266 is likely a flaring star
  34. Swift Trigger 1434591 is not a GRB
  35. GRB 260111A: GOTO optical upper limits
  36. GRB 260112B: Fermi GBM Final Real-time Localization
  37. GRB 260111A: Swift ToO observations
  38. GRB 251230A: Mondy Optical Observations
  39. GRB 260111A: Swift/BAT-GUANO arcminute localization of a burst
  40. GRB 260112A: Fermi GBM Final Real-time Localization
  41. EP260110a: SVOM/VT optical upper limits
  42. IceCube-260111A - IceCube observation of a high-energy neutrino candidate track-like event
  43. IceCube Alert 260111A: Global MASTER-Net observations report
  44. EP260110a: Global MASTER-Net observations report
  45. Fermi GRB 260111A: Global MASTER-Net observations report
  46. GRB 260111A: Fermi GBM Final Real-time Localization
  47. Swift trigger 1436759 is not an astrophysical event
  48. EP260110a: KAIT optical upper limit
  49. EP260110a: refined analysis of the EP-WXT and EP-FXT observations
  50. EP 260110a: COLIBRÍ optical observations
  51. EP260110a: SVOM/C-GFT upper limit
  52. EP260110a: BOOTES-5/JGU optical upper limit
  53. EP260110a: Einstein Probe detection of an X-ray transient
  54. GRB 260109C: LCO optical upper limits
  55. GRB 260109C: Kilonova-Catcher optical upper limit
  56. EP260105b / GRB 260105C : Fermi-GBM Sub-Threshold Detection
  57. Swift Trigger 1434591: possible GRB 260109C
  58. GRB 260109B: Fermi GBM Final Real-time Localization
  59. GRB 260102A: Swift-XRT afterglow detection
  60. GRB 260109A: Fermi GBM Final Real-time Localization
  61. GRB 260104A: Swift-BAT refined analysis
  62. GRB 260101A: Swift-BAT refined analysis
  63. Swift GRB 251230A: Global MASTER-Net OT detection
  64. Fermi GRB 260107A: Global MASTER-Net observations report
  65. GRB 260102A: AbAO optical observations
  66. GRB 260107A: Fermi GBM Final Real-time Localization
  67. EP260105b/EP-WXT trigger 01709251028: Einstein Probe detection of an X-ray transient
  68. The EP-WXT trigger 01709251112 is likely a flaring star
  69. Fermi GRB 260105A: Global MASTER-Net observations report
  70. GRB 260105B: Fermi GBM Detection
  71. EP260105a: FTW optical observations
  72. EP260104a: FTW optical observations
  73. GRB 260105B: BALROG localization (Fermi Trigger 789348101 / GRB 260105973)
  74. GRB 260105A: SVOM/GRM observation
  75. GRB 260105B: SVOM/GRM observation
  76. The EP-WXT trigger 01709251028 is likely a flaring star
  77. FRB 20251229A: COLIBRÍ optical upper limits
  78. Fermi GRB 260105B: Global MASTER-Net observations report
  79. EP260105a: SVOM/VT optical upperlimit
  80. GRB 260105B: Fermi GBM Final Real-time Localization
  81. GRB 260105A: Fermi GBM Final Real-time Localization
  82. FRB 20251229A: A potentially hyperactive repeating fast radio burst source
  83. EP260105a: refined analysis of the EP-WXT and EP-FXT observations
  84. EP260105a: LCO Optical Upper limit
  85. EP260104a: Global MASTER-Net observations report
  86. EP260104a: Einstein Probe detection of a fast X-ray transient
  87. GRB 260101A: COLIBRÍ optical upper limits
  88. EP260105a: Global MASTER-Net observations report
  89. EP260105a: Einstein Probe detection of an X-ray transient
  90. GRB 260103A: Insight-HXMT/HE detection
  91. GRB 260104A: COLIBRÍ optical upper limits
  92. GRB 260104C: Fermi GBM Final Real-time Localization
  93. Fermi GRB 260104B: Global MASTER-Net observations report
  94. Swift GRB 260104A: Global MASTER-Net observations report
  95. GRB 251230A/EP-WXT trigger 01709250693: Mephisto optical upper limits
  96. GRB 260104A: Swift-XRT refined Analysis
  97. GRB 260104A: Enhanced Swift-XRT position
  98. GRB 260101A: Swift/UVOT Detection
  99. GRB 260103A: GECAM-B observation of a burst
  100. GRB 260104B: Fermi GBM Final Localization

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