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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"

38646 results found.

  1. GRB 260114A: VLT/HAWK-I further near-infrared upper limits
  2. IceCube-260115A - IceCube observation of a high-energy neutrino candidate track-like event
  3. GRB 260115A: BALROG localization (Fermi Trigger 790192010 / GRB 260115741)
  4. IceCube: GCN Notices for high-energy track alerts now streamed via Kafka
  5. GRB 260115A: Fermi GBM Final Real-time Localization
  6. GRB260114A: STEP/T80S optical limits
  7. GRB 251222A: radio detection with the VLA
  8. GRB 260114A: VLT/HAWK-I near-infrared upper limits
  9. Konus-Wind detection of GRB 260114A
  10. GRB 260114A: Swift-XRT refined Analysis
  11. GRB 260114A: 6 GHz VLA observations
  12. GRB 260114A: VLT/X-shooter redshift of the putative host galaxy
  13. GRB 260114A : MITSuME Akeno optical upper limits
  14. GRB 260114A: COLIBRÍ optical upper limits
  15. GRB 260114A: TNG NIR upper limit
  16. GRB 260114A: NOT optical observations
  17. Konus-Wind detection of GRB 251230A / EP251230a
  18. GRB 260114A: SVOM/GRM observation of a short burst
  19. GRB 260114A: GECAM-B observation of a short burst
  20. GRB 260114A: Mondy optical observations
  21. GRB 260114A: Fermi GBM observation
  22. GRB 260112B: GECAM-B observation
  23. GRB 260114A: GMG Optical Observation
  24. Fermi-LAT Gamma-ray Observations of IceCube-260111A
  25. GRB 260114A: Swift detection of a short burst
  26. GRB 260114A: Fermi GBM Final Real-time Localization
  27. EP-WXT trigger 01709251266: SVOM/C-GFT confirmation of a stellar flare
  28. IceCube-260111A: Upper limits from a search for additional neutrino events in IceCube
  29. EP260110a: NOT and GTC Optical and Near-Infrared Observations
  30. EP260110a: TRT optical upper limits
  31. Konus-Wind detection of GRB 260101A
  32. GRB 260111A: Swift-XRT observations
  33. Swift Trigger 1439093: is probably not GRB 260113A
  34. GRB 260111A: COLIBRÍ optical afterglow candidate
  35. GRB 260111A: GECAM-B observation of a burst
  36. GRB 260111A: Fermi GBM Observation
  37. The EP-WXT trigger 01709251266 is likely a flaring star
  38. Swift Trigger 1434591 is not a GRB
  39. GRB 260111A: GOTO optical upper limits
  40. GRB 260112B: Fermi GBM Final Real-time Localization
  41. GRB 260111A: Swift ToO observations
  42. GRB 251230A: Mondy Optical Observations
  43. GRB 260111A: Swift/BAT-GUANO arcminute localization of a burst
  44. GRB 260112A: Fermi GBM Final Real-time Localization
  45. EP260110a: SVOM/VT optical upper limits
  46. IceCube-260111A - IceCube observation of a high-energy neutrino candidate track-like event
  47. GRB 260111A: Fermi GBM Final Real-time Localization
  48. Swift trigger 1436759 is not an astrophysical event
  49. EP260110a: KAIT optical upper limit
  50. EP260110a: refined analysis of the EP-WXT and EP-FXT observations
  51. EP 260110a: COLIBRÍ optical observations
  52. EP260110a: SVOM/C-GFT upper limit
  53. EP260110a: BOOTES-5/JGU optical upper limit
  54. EP260110a: Einstein Probe detection of an X-ray transient
  55. GRB 260109C: LCO optical upper limits
  56. GRB 260109C: Kilonova-Catcher optical upper limit
  57. EP260105b / GRB 260105C : Fermi-GBM Sub-Threshold Detection
  58. Swift Trigger 1434591: possible GRB 260109C
  59. GRB 260109B: Fermi GBM Final Real-time Localization
  60. GRB 260102A: Swift-XRT afterglow detection
  61. GRB 260109A: Fermi GBM Final Real-time Localization
  62. Swift GRB 251230A: Global MASTER-Net OT detection
  63. GRB 260102A: AbAO optical observations
  64. GRB 260107A: Fermi GBM Final Real-time Localization
  65. EP260105b/EP-WXT trigger 01709251028: Einstein Probe detection of an X-ray transient
  66. The EP-WXT trigger 01709251112 is likely a flaring star
  67. GRB 260105B: Fermi GBM Detection
  68. GRB 260105B: BALROG localization (Fermi Trigger 789348101 / GRB 260105973)
  69. GRB 260105A: SVOM/GRM observation
  70. GRB 260105B: SVOM/GRM observation
  71. The EP-WXT trigger 01709251028 is likely a flaring star
  72. FRB 20251229A: COLIBRÍ optical upper limits
  73. EP260105a: SVOM/VT optical upperlimit
  74. GRB 260105B: Fermi GBM Final Real-time Localization
  75. GRB 260105A: Fermi GBM Final Real-time Localization
  76. FRB 20251229A: A potentially hyperactive repeating fast radio burst source
  77. EP260105a: refined analysis of the EP-WXT and EP-FXT observations
  78. EP260105a: LCO Optical Upper limit
  79. EP260104a: Einstein Probe detection of a fast X-ray transient
  80. GRB 260101A: COLIBRÍ optical upper limits
  81. EP260105a: Einstein Probe detection of an X-ray transient
  82. GRB 260103A: Insight-HXMT/HE detection
  83. GRB 260104A: COLIBRÍ optical upper limits
  84. GRB 260104C: Fermi GBM Final Real-time Localization
  85. GRB 251230A/EP-WXT trigger 01709250693: Mephisto optical upper limits
  86. GRB 260104A: Swift-XRT refined Analysis
  87. GRB 260104A: Enhanced Swift-XRT position
  88. GRB 260101A: Swift/UVOT Detection
  89. GRB 260103A: GECAM-B observation of a burst
  90. GRB 260104B: Fermi GBM Final Localization
  91. GRB 260104A: Swift detection of a burst
  92. GRB 260103A: SVOM/GRM observation of a possible GRB
  93. Fermi-LAT Gamma-ray Observations of IceCube-251225A
  94. GRB 260101A: COLIBRÍ optical observations
  95. SVOM GRB260103.08: Global MASTER-Net observations report
  96. GRB 260102B: Fermi GBM Final Real-time Localization
  97. SVOM GRB260102A: Global MASTER-Net observations report
  98. Fermi GBM Sub-Threshold Detection of GRB 260102A
  99. GRB 260102A: EP-FXT follow-up observation
  100. GRB 260102A: LCO optical upper limits

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