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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"

28260 results found.

  1. EP260116a: Global MASTER-Net observations report
  2. GRB 260111A: COLIBRÍ fading of the optical counterpart candidate
  3. EP260116a: Xinglong optical upper limit
  4. EP260116a: Einstein Probe detection of an X-ray transient
  5. GRB 260114A: VLT/HAWK-I further near-infrared upper limits
  6. IceCube Alert 260115.73: Global MASTER-Net observations report
  7. GRB 260115A: BALROG localization (Fermi Trigger 790192010 / GRB 260115741)
  8. IceCube: GCN Notices for high-energy track alerts now streamed via Kafka
  9. Fermi GRB 260115A: Global MASTER-Net observations report
  10. GRB 251222A: radio detection with the VLA
  11. GRB 260114A: VLT/HAWK-I near-infrared upper limits
  12. GRB 260114A: Swift-XRT refined Analysis
  13. GRB 260114A: VLT/X-shooter redshift of the putative host galaxy
  14. GRB 260114A : MITSuME Akeno optical upper limits
  15. GRB 260114A: COLIBRÍ optical upper limits
  16. GRB 260114A: TNG NIR upper limit
  17. GRB 260114A: NOT optical observations
  18. GRB 260114A: SVOM/GRM observation of a short burst
  19. Swift GRB 260114A: Global MASTER-Net observations report
  20. GRB 260114A: Mondy optical observations
  21. GRB 260114A: GMG Optical Observation
  22. Fermi-LAT Gamma-ray Observations of IceCube-260111A
  23. GRB 260114A: Swift detection of a short burst
  24. EP-WXT trigger 01709251266: SVOM/C-GFT confirmation of a stellar flare
  25. IceCube-260111A: Upper limits from a search for additional neutrino events in IceCube
  26. Swift GRB260113.43: Global MASTER-Net observations report
  27. EP260110a: NOT and GTC Optical and Near-Infrared Observations
  28. EP260110a: TRT optical upper limits
  29. Konus-Wind detection of GRB 260101A
  30. GRB 260111A: Swift-XRT observations
  31. Swift Trigger 1439093: is probably not GRB 260113A
  32. GRB 260111A: COLIBRÍ optical afterglow candidate
  33. GRB 260111A: Fermi GBM Observation
  34. GRB 251230A: Mondy Optical Observations
  35. GRB 260111A: Swift/BAT-GUANO arcminute localization of a burst
  36. IceCube Alert 260111A: Global MASTER-Net observations report
  37. EP260110a: Global MASTER-Net observations report
  38. Fermi GRB 260111A: Global MASTER-Net observations report
  39. Swift trigger 1436759 is not an astrophysical event
  40. EP260110a: KAIT optical upper limit
  41. EP260110a: refined analysis of the EP-WXT and EP-FXT observations
  42. EP 260110a: COLIBRÍ optical observations
  43. EP260110a: SVOM/C-GFT upper limit
  44. EP260110a: Einstein Probe detection of an X-ray transient
  45. GRB 260109C: LCO optical upper limits
  46. GRB 260109C: Kilonova-Catcher optical upper limit
  47. EP260105b / GRB 260105C : Fermi-GBM Sub-Threshold Detection
  48. Swift Trigger 1434591: possible GRB 260109C
  49. GRB 260102A: Swift-XRT afterglow detection
  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. EP260105b/EP-WXT trigger 01709251028: Einstein Probe detection of an X-ray transient
  56. Fermi GRB 260105A: Global MASTER-Net observations report
  57. GRB 260105B: Fermi GBM Detection
  58. GRB 260105B: BALROG localization (Fermi Trigger 789348101 / GRB 260105973)
  59. GRB 260105A: SVOM/GRM observation
  60. GRB 260105B: SVOM/GRM observation
  61. FRB 20251229A: COLIBRÍ optical upper limits
  62. Fermi GRB 260105B: Global MASTER-Net observations report
  63. FRB 20251229A: A potentially hyperactive repeating fast radio burst source
  64. EP260105a: refined analysis of the EP-WXT and EP-FXT observations
  65. EP260105a: LCO Optical Upper limit
  66. EP260104a: Global MASTER-Net observations report
  67. EP260104a: Einstein Probe detection of a fast X-ray transient
  68. GRB 260101A: COLIBRÍ optical upper limits
  69. EP260105a: Global MASTER-Net observations report
  70. EP260105a: Einstein Probe detection of an X-ray transient
  71. GRB 260104A: COLIBRÍ optical upper limits
  72. Fermi GRB 260104B: Global MASTER-Net observations report
  73. Swift GRB 260104A: Global MASTER-Net observations report
  74. GRB 251230A/EP-WXT trigger 01709250693: Mephisto optical upper limits
  75. GRB 260104A: Swift-XRT refined Analysis
  76. GRB 260104A: Enhanced Swift-XRT position
  77. GRB 260101A: Swift/UVOT Detection
  78. GRB 260103A: GECAM-B observation of a burst
  79. GRB 260104A: Swift detection of a burst
  80. Fermi-LAT Gamma-ray Observations of IceCube-251225A
  81. GRB 260101A: COLIBRÍ optical observations
  82. SVOM GRB260103.08: Global MASTER-Net observations report
  83. SVOM GRB260102A: Global MASTER-Net observations report
  84. Fermi GBM Sub-Threshold Detection of GRB 260102A
  85. GRB 260102A: EP-FXT follow-up observation
  86. EP260101a: Global MASTER-Net observations report
  87. GRB 260102A: LCO optical upper limits
  88. GRB 260102A: Swift-XRT observations
  89. GRB 260102A: SVOM/COLIBRÍ (FM-GFT) optical observations
  90. GRB 260101A: Fermi GBM Observation
  91. EP260101a: refined analysis of the EP-WXT and EP-FXT observations
  92. GRB 260102A: SVOM detection of a burst
  93. GRB 260101A: NOT spectroscopic observations
  94. GRB 260101A: SVOM/GRM observation
  95. GRB 260101A: Swift-XRT refined Analysis
  96. Swift GRB 260101A: Global MASTER-Net observations report
  97. GRB 260101A: Enhanced Swift-XRT position
  98. EP260101a: Einstein Probe detection of an X-ray transient
  99. GRB 260101A: LCO detection of the optical counterpart
  100. GRB 260101A: Swift detection of a burst with an optical counterpart

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