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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"

21069 results found.

  1. The first three GRBs detected by SVOM: GRB 240627B, GRB 240629A and GRB 240702A
  2. Fermi GRB 240702A: Global MASTER-Net observations report
  3. EP240702a: EP-WXT detection of a fast X-ray transient
  4. Fermi trigger No 741448122: Global MASTER-Net observations report
  5. LIGO/Virgo/KAGRA S240629by: Upper limits from Fermi-GBM Observations
  6. LIGO/Virgo/KAGRA S240629by: Coverage and upper limits from MAXI/GSC observations
  7. Fermi trigger No 741356809: Global MASTER-Net observations report
  8. Fermi GRB 240629A: Global MASTER-Net observations report
  9. Fermi trigger No 741296200: Global MASTER-Net observations report
  10. Fermi trigger No 741251380: Global MASTER-Net observations report
  11. GRB 240615A: SAI CMO J- band observations
  12. Fermi trigger No 741211696: Global MASTER-Net observations report
  13. EP240626a: Montarrenti Observatory optical upper limit
  14. EP240625a: GRANDMA Optical Upper Limits
  15. EP240626a: EP-WXT detection of a fast X-ray transient
  16. Fermi GRB 240625B: Global MASTER-Net observations report
  17. EP240625a: NOT optical counterpart candidate
  18. EP240625a: EP-WXT detection of a fast X-ray transient
  19. Swift GRB 240624A: Global MASTER-Net observations report
  20. GRB240615A: Gemini-North observations of the BAT and XRT positions
  21. Fermi GRB 240624A: Global MASTER-Net observations report
  22. Fermi trigger No 740949590: Global MASTER-Net observations report
  23. GRB240615A: Gemini-North observations of the BAT and XRT positions
  24. GRB 240619A: detection of a radio counterpart with AMI-LA
  25. EP240618a: NOT further optical observations
  26. GRB 240619A: J-band detection with WINTER
  27. Fermi trigger No 740744838: Global MASTER-Net observations report
  28. EP240618a: NOT optical counterpart candidate
  29. GRB 240529A: JinShan optical observations
  30. EP240618a: GSP optical upper limit
  31. EP240617a: tentative Swift/XRT detection of the afterglow
  32. GRB 240619A: Swift-XRT probable afterglow detection
  33. GRB 240619A: Swift ToO observations
  34. GRB 240619A: GOTO candidate optical afterglow
  35. EP240618a: Abastumani optical observationsEP240618a
  36. GRB 240615A: NOT optical observations
  37. EP240618a: GRANDMA Optical Upper Limits
  38. EP240618a: TRT optical upper limit
  39. Fermi trigger No 740474239: Global MASTER-Net observations report
  40. Fermi GRB 240619A: Global MASTER-Net observations report
  41. EP240617a: STEP/T80S optical limits
  42. GRB 240615A: possible transient detection from Wendelstein observations
  43. LIGO/Virgo S240615dg: GRANDMA/FRAM-CTA-N Observations
  44. EP240618a: OHP/T193 MISTRAL i' and Y band upper limits
  45. LIGO/Virgo S240615dg: Swift XRT observations, 39 X-ray sources
  46. Fermi trigger No 740430582: Global MASTER-Net observations report
  47. EP240617a: EP-WXT detection of a fast X-ray transient
  48. EP240618a: EP-WXT detection of a fast X-ray transient and EP-FXT quick follow-up
  49. GRB 240615A: J-band upper limits from WINTER
  50. GRB 240615A: Swift-XRT observations
  51. X-ray transient EP240414a: Chandra late time observation
  52. Fermi trigger No 740221779: Global MASTER-Net observations report
  53. Fermi GRB 240616A: Global MASTER-Net observations report
  54. GRB 240615A: GOTO optical upper limits
  55. Fermi trigger No 740166710: Global MASTER-Net observations report
  56. GRB 240615A: Swift ToO observations
  57. GRB 240615A: Swift/BAT-GUANO arcminute localization of a short burst
  58. Fermi GRB 240612B: Global MASTER-Net observations report
  59. Fermi GRB 240612A: Global MASTER-Net observations report
  60. Fermi GRB 240611A: Global MASTER-Net observations report
  61. GRB 240529A: LBT optical detection and late temporal decay
  62. Trigger 1236151: Swift detection of EXO 0748-676
  63. Fermi GRB 240610A: Global MASTER-Net observations report
  64. Fermi trigger No 739632045: Global MASTER-Net observations report
  65. Fermi GRB 240608A: Global MASTER-Net observations report
  66. Fermi trigger No 739506569: Global MASTER-Net observations report
  67. Fermi GRB 240607A: Global MASTER-Net observations report
  68. GRB 240529A: NOEMA detection
  69. GRB 240607A: Fermi GBM detection of a very bright burst
  70. GRB 240529A: radio detection with AMI-LA
  71. Fermi trigger No 739373591: Global MASTER-Net observations report
  72. GRB 240606B: Swift-XRT afterglow detection
  73. Swift GRB240606.15: Global MASTER-Net observations report
  74. GRB 240606B: Swift ToO observations
  75. GRB 240606B: Swift/BAT-GUANO arcminute localization of a burst
  76. Fermi GRB 240604A: Global MASTER-Net observations report
  77. Fermi GRB 240605A: Global MASTER-Net observations report
  78. Fermi GRB 240605C: Global MASTER-Net observations report
  79. GRB 240529A: SAO RAS optical observations
  80. Fermi GRB 240603C: Global MASTER-Net observations report
  81. GRB 240529A: MASTER prompt OT detection
  82. GRB 240529A: continued SAO RAS optical observations
  83. Fermi GRB 240602A: Global MASTER-Net observations report
  84. GRB 240529A: OSN optical detection
  85. GRB 240529A: further SAO RAS optical observations
  86. GRB 240529A: AKO Optical Afterglow Follow-Up Observations
  87. LXT 240528A: GSP optical upper limit
  88. GRB 240529A: 1.3m DFOT Optical observations
  89. GRB 240529A : Mondy optical observations
  90. GRB 240529A: SAO RAS optical observations
  91. GRB 240529A: optical photometry from Konkoly
  92. GRB 240529A: T193/MISTRAL observations
  93. GRB 240529A: AKO Optical Afterglow Detection
  94. GRB 240529A: J-band detections with WINTER
  95. GRB 240529A: Skynet Optical Observations
  96. LXT 240528A: LEIA detection of a fast X-ray transient
  97. LIGO/Virgo S240527fv: GRANDMA/FRAM-Auger Optical Observations
  98. GRB 240529A: Swift/UVOT Detection
  99. GRB 240529A: NOT optical observations
  100. GRB 240529A: GOTO optical afterglow detection

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Download all Circulars as a .tar.gz archive (updated once a day):
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