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GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. 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"

39220 results found.

  1. GRB 240624B: CALET Gamma-Ray Burst Monitor detection
  2. GRB 240625B: Fermi GBM Final Real-time Localization
  3. GRB 240625A: Fermi GBM Observation
  4. GRB 240624B: GRBAlpha detection
  5. GRB 240625A: Fermi GBM Final Real-time Localization
  6. GRB240624A: Fermi GBM Observation
  7. LIGO/Virgo/KAGRA S240622h: Upper limits from Swift/BAT-GUANO
  8. LIGO/Virgo/KAGRA S240621dy: Upper limits from Swift/BAT-GUANO
  9. LIGO/Virgo/KAGRA S240618ah: Upper limits from Swift/BAT-GUANO
  10. Swift GRB 240624A: Global MASTER-Net observations report
  11. GRB240615A: Gemini-North observations of the BAT and XRT positions
  12. Fermi GRB 240624A: Global MASTER-Net observations report
  13. GRB 240624B: Fermi GBM Final Real-time Localization
  14. Fermi trigger No 740949590: Global MASTER-Net observations report
  15. GRB240615A: Gemini-North observations of the BAT and XRT positions
  16. GRB 240624A: Fermi GBM Final Real-time Localization
  17. GRB 240619A: detection of a radio counterpart with AMI-LA
  18. GRB 240624A: Swift detection of a burst
  19. GRB 240619A: J-band detection with WINTER (duplicate submission of GCN 36739)
  20. GRB 240619A: J-band detection with WINTER
  21. Fermi trigger No 740744838: Global MASTER-Net observations report
  22. EP240618a: NOT optical counterpart candidate
  23. GRB 240529A: JinShan optical observations
  24. EP240618a: GSP optical upper limit
  25. IPN triangulation of GRB 240615A (short)
  26. GRB 240619A: GRBAlpha detection
  27. GRB 240619A: Swift-XRT probable afterglow detection
  28. GRB 240619A: Swift ToO observations
  29. GRB 240619A: CALET Gamma-Ray Burst Monitor detection
  30. GRB 240619C: NuSTAR automated detection of the GRB
  31. GRB 240619A: Fermi GBM Observation
  32. Fermi GBM Sub-Threshold Detection of GRB 240619C
  33. GRB 240619A: GOTO candidate optical afterglow
  34. EP240618a: Abastumani optical observationsEP240618a
  35. GRB 240615A: NOT optical observations
  36. GRB 240619C: AstroSat CZTI detection
  37. EP240618a: TRT optical upper limit
  38. Fermi trigger No 740474239: Global MASTER-Net observations report
  39. Fermi GRB 240619A: Global MASTER-Net observations report
  40. GRB 240615A: possible transient detection from Wendelstein observations
  41. LIGO/Virgo S240615dg: GRANDMA/FRAM-CTA-N Observations
  42. EP240618a: OHP/T193 MISTRAL i' and Y band upper limits
  43. Fermi Gamma-ray Burst Monitor trigger 740474239/240619304 is not a GRB
  44. GRB 240619B: Fermi GBM Final Real-time Localization
  45. Fermi trigger No 740430582: Global MASTER-Net observations report
  46. GRB240615A: 1.3m DFOT optical upper limit
  47. GRB 240619A: BALROG localization (Fermi Trigger 740461416 / GRB 240619155)
  48. GRB 240619A: Fermi GBM Final Real-time Localization
  49. EP240617a: BOOTES-6/DPRT optical upper limit
  50. EP240617a is likely a GRB event
  51. LIGO/Virgo/KAGRA S240615ea: Upper limits from Swift/BAT-GUANO
  52. LIGO/Virgo/KAGRA S240615dg: Upper limits from Swift/BAT-GUANO
  53. GRB 240615A: J-band upper limits from WINTER
  54. GRB 240615A: Fermi GBM Observation
  55. GRB 240615A: Swift-XRT observations
  56. GRB 240615A: GECAM detection
  57. GRB 240615A: FLWO-1.2m optical upper limits
  58. Fermi trigger No 740221779: Global MASTER-Net observations report
  59. Fermi GRB 240616A: Global MASTER-Net observations report
  60. Konus-Wind detection of GRB 240615A (short/hard)
  61. GRB 240615A: GOTO optical upper limits
  62. Fermi trigger No 740166710: Global MASTER-Net observations report
  63. GRB 240616A: Fermi GBM Final Real-time Localization
  64. GRB 240615A: Swift ToO observations
  65. GRB 240615A: Swift/BAT-GUANO arcminute localization of a short burst
  66. GRB 240615A: Fermi GBM Final Real-time Localization
  67. GRB 240603A: VZLUSAT-2 detection
  68. GRB 240612A: GRBAlpha detection
  69. GRB 240613A: Fermi GBM Final Real-time Localization
  70. Fermi GRB 240612B: Global MASTER-Net observations report
  71. Fermi GRB 240612A: Global MASTER-Net observations report
  72. GRB 240612B: Fermi GBM Final Real-time Localization
  73. GRB 240612A: Fermi GBM Final Real-time Localization
  74. GRB 240607A: GECAM detection of a bright long burst
  75. Fermi GRB 240611A: Global MASTER-Net observations report
  76. Konus-Wind detection of GRB 240607A
  77. GRB 240611A: Fermi GBM Final Real-time Localization
  78. GRB 240529A: LBT optical detection and late temporal decay
  79. GRB 240529A : MITSuME Akeno optical afterglow detection
  80. Trigger 1236151: Swift detection of EXO 0748-676
  81. Fermi GRB 240610A: Global MASTER-Net observations report
  82. GRB 240610A: Fermi GBM Final Real-time Localization
  83. IPN triangulation of GRB 240607A
  84. Fermi Gamma-ray Burst Monitor trigger 739632045/240609556 is not a GRB
  85. Fermi trigger No 739632045: Global MASTER-Net observations report
  86. Fermi GRB 240608A: Global MASTER-Net observations report
  87. Konus-Wind detection of GRB 240606B
  88. Fermi trigger No 739506569: Global MASTER-Net observations report
  89. GRB 240608A: Fermi GBM Final Real-time Localization
  90. Fermi GRB 240607A: Global MASTER-Net observations report
  91. GRB 240529A: NOEMA detection
  92. GRB 240607A: Fermi GBM Observation
  93. GRB 240606B: Fermi GBM Observation
  94. Swift Trigger 1235109: consistent with noise and not astrophysical
  95. GRB 240607A: AstroSat CZTI detection of bright long burst
  96. GRB 240607A: Fermi GBM detection of a very bright burst
  97. GRB 240529A: radio detection with AMI-LA
  98. GRB 240607A: BALROG localization (Fermi Trigger 739450879 / GRB 240607459)
  99. GRB 240607A: Fermi GBM Final Real-time Localization
  100. GRB 240606B: GECAM-B detection a long burst

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