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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"

45602 results found.

  1. EP260116a: Einstein Probe detection of an X-ray transient
  2. GRB 260114A: VLT/HAWK-I further near-infrared upper limits
  3. IceCube Alert 260115.73: Global MASTER-Net observations report
  4. IceCube-260115A - IceCube observation of a high-energy neutrino candidate track-like event
  5. GRB 260115A: BALROG localization (Fermi Trigger 790192010 / GRB 260115741)
  6. IceCube: GCN Notices for high-energy track alerts now streamed via Kafka
  7. Fermi GRB 260115A: Global MASTER-Net observations report
  8. GRB 260115A: Fermi GBM Final Real-time Localization
  9. GRB260114A: STEP/T80S optical limits
  10. GRB 251222A: radio detection with the VLA
  11. GRB 260114A: VLT/HAWK-I near-infrared upper limits
  12. Konus-Wind detection of GRB 260114A
  13. GRB 260114A: Swift-XRT refined Analysis
  14. GRB 260114A: 6 GHz VLA observations
  15. GRB 260114A: VLT/X-shooter redshift of the putative host galaxy
  16. GRB 260114A : MITSuME Akeno optical upper limits
  17. GRB 260114A: COLIBRÍ optical upper limits
  18. GRB 260114A: TNG NIR upper limit
  19. GRB 260114A: NOT optical observations
  20. Konus-Wind detection of GRB 251230A / EP251230a
  21. GRB 260114A: SVOM/GRM observation of a short burst
  22. Swift GRB 260114A: Global MASTER-Net observations report
  23. GRB 260114A: GECAM-B observation of a short burst
  24. GRB 260114A: Mondy optical observations
  25. GRB 260114A: Fermi GBM observation
  26. GRB 260112B: GECAM-B observation
  27. GRB 260114A: GMG Optical Observation
  28. Fermi-LAT Gamma-ray Observations of IceCube-260111A
  29. GRB 260114A: Swift detection of a short burst
  30. GRB 260114A: Fermi GBM Final Real-time Localization
  31. EP-WXT trigger 01709251266: SVOM/C-GFT confirmation of a stellar flare
  32. IceCube-260111A: Upper limits from a search for additional neutrino events in IceCube
  33. Swift GRB260113.43: Global MASTER-Net observations report
  34. EP260110a: NOT and GTC Optical and Near-Infrared Observations
  35. EP260110a: TRT optical upper limits
  36. Konus-Wind detection of GRB 260101A
  37. GRB 260111A: Swift-XRT observations
  38. Swift Trigger 1439093: is probably not GRB 260113A
  39. GRB 260111A: COLIBRÍ optical afterglow candidate
  40. GRB 260111A: GECAM-B observation of a burst
  41. GRB 260111A: Fermi GBM Observation
  42. The EP-WXT trigger 01709251266 is likely a flaring star
  43. Swift Trigger 1434591 is not a GRB
  44. GRB 260111A: GOTO optical upper limits
  45. GRB 260112B: Fermi GBM Final Real-time Localization
  46. GRB 260111A: Swift ToO observations
  47. GRB 251230A: Mondy Optical Observations
  48. GRB 260111A: Swift/BAT-GUANO arcminute localization of a burst
  49. GRB 260112A: Fermi GBM Final Real-time Localization
  50. EP260110a: SVOM/VT optical upper limits
  51. IceCube-260111A - IceCube observation of a high-energy neutrino candidate track-like event
  52. IceCube Alert 260111A: Global MASTER-Net observations report
  53. EP260110a: Global MASTER-Net observations report
  54. Fermi GRB 260111A: Global MASTER-Net observations report
  55. GRB 260111A: Fermi GBM Final Real-time Localization
  56. Swift trigger 1436759 is not an astrophysical event
  57. EP260110a: KAIT optical upper limit
  58. EP260110a: refined analysis of the EP-WXT and EP-FXT observations
  59. EP 260110a: COLIBRÍ optical observations
  60. EP260110a: SVOM/C-GFT upper limit
  61. EP260110a: BOOTES-5/JGU optical upper limit
  62. EP260110a: Einstein Probe detection of an X-ray transient
  63. GRB 260109C: LCO optical upper limits
  64. GRB 260109C: Kilonova-Catcher optical upper limit
  65. EP260105b / GRB 260105C : Fermi-GBM Sub-Threshold Detection
  66. Swift Trigger 1434591: possible GRB 260109C
  67. GRB 260109B: Fermi GBM Final Real-time Localization
  68. GRB 260102A: Swift-XRT afterglow detection
  69. GRB 260109A: Fermi GBM Final Real-time Localization
  70. GRB 260104A: Swift-BAT refined analysis
  71. GRB 260101A: Swift-BAT refined analysis
  72. Swift GRB 251230A: Global MASTER-Net OT detection
  73. Fermi GRB 260107A: Global MASTER-Net observations report
  74. GRB 260102A: AbAO optical observations
  75. GRB 260107A: Fermi GBM Final Real-time Localization
  76. EP260105b/EP-WXT trigger 01709251028: Einstein Probe detection of an X-ray transient
  77. The EP-WXT trigger 01709251112 is likely a flaring star
  78. Fermi GRB 260105A: Global MASTER-Net observations report
  79. GRB 260105B: Fermi GBM Detection
  80. EP260105a: FTW optical observations
  81. EP260104a: FTW optical observations
  82. GRB 260105B: BALROG localization (Fermi Trigger 789348101 / GRB 260105973)
  83. GRB 260105A: SVOM/GRM observation
  84. GRB 260105B: SVOM/GRM observation
  85. The EP-WXT trigger 01709251028 is likely a flaring star
  86. FRB 20251229A: COLIBRÍ optical upper limits
  87. Fermi GRB 260105B: Global MASTER-Net observations report
  88. EP260105a: SVOM/VT optical upperlimit
  89. GRB 260105B: Fermi GBM Final Real-time Localization
  90. GRB 260105A: Fermi GBM Final Real-time Localization
  91. FRB 20251229A: A potentially hyperactive repeating fast radio burst source
  92. EP260105a: refined analysis of the EP-WXT and EP-FXT observations
  93. EP260105a: LCO Optical Upper limit
  94. EP260104a: Global MASTER-Net observations report
  95. EP260104a: Einstein Probe detection of a fast X-ray transient
  96. GRB 260101A: COLIBRÍ optical upper limits
  97. EP260105a: Global MASTER-Net observations report
  98. EP260105a: Einstein Probe detection of an X-ray transient
  99. GRB 260103A: Insight-HXMT/HE detection
  100. GRB 260104A: COLIBRÍ optical upper limits

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