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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"

11533 results found.

  1. Fermi Gamma-ray Burst Monitor trigger 260428446 is not a GRB
  2. GRB 090328: Fermi-LAT refined analysis
  3. GRB 090331: Fermi GBM detection
  4. GRB 090328B: MASTER-Irkutsk prompt optical short burst observations
  5. GRB 090323: Further TLS detections - a break?
  6. GRB 090328: Radio afterglow detection
  7. GRB 090326: Fermi GBM detection
  8. GRB 090328: BOOTES-3 optical observations
  9. GRB 090328: Fermi GBM Spectral Analysis
  10. GRB 090328B: Fermi GBM Detection
  11. GRB 090330: Fermi GBM detection
  12. GRB 090328: GROND Detection of the Optical/NIR Afterglow
  13. GRB 090328: Gemini South Redshift
  14. GRB 090328: Swift XRT refined analysis
  15. Konus-Wind observation of GRB 090328
  16. GRB 090328: IPN Triangulation
  17. GRB 090328: Swift UVOT observations
  18. Fermi LAT and GBM detections of GRB090328
  19. GRB 090323: Radio afterglow detection
  20. GRB 090323: TLS detection at 5 days, no break
  21. GRB 090327: Fermi GBM detection
  22. GRB 090323: Faulkes Telescope South Observations
  23. GRB 090320B: MASTER-Net prompt optical observations
  24. GRB 090323: Fermi GBM Spectral Analysis
  25. GRB 090323 TLS detection - still bright
  26. GRB 090323: UVOT Detection of Afterglow
  27. GRB 090323: Swift-XRT refined analysis
  28. Konus-Wind observation of GRB 090323
  29. GRB 090323: GROND Detection of the Afterglow and Photo-z
  30. SGR J1550-5418: two Fermi GBM triggers on March 22
  31. GRB 090323: Possible XRT Counterpart
  32. IPN triangulation of GRB090323
  33. GRB 090320C: Fermi GBM Detection
  34. Fermi GBM and LAT detections of GRB 090323
  35. GRB 090320B: Fermi GBM detection.
  36. GRB 090319: Fermi GBM detection
  37. GRB 090320A: Fermi GBM detection
  38. GRB090305B: MASTER-net prompt optical short burst observations
  39. GRB090310: Fermi GBM detection
  40. GRB090305B: Fermi GBM detection
  41. GRB 090309B: Fermi GBM detection
  42. GRB 090308B: Fermi GBM detection
  43. GRB 090307B: Fermi GBM detection
  44. GRB 090306C: Fermi GBM detection
  45. Fermi GBM trigger 090305784 is not a GRB
  46. GRB 090303: Fermi GBM detection
  47. GRB 090304: Fermi GBM detection
  48. Konus-RF catches first GRB and SGR bursts
  49. GRB 090228B: Fermi GBM detection
  50. Konus-Wind observation of bright short GRB 090227B
  51. IPN localization of short bright GRB 090227B
  52. GRB 090301B: Fermi GBM detection
  53. GRB 090227B: Fermi GBM detection
  54. GRB 090228: Fermi GBM detection
  55. GRB 090227: Fermi GBM detection
  56. GRB 090206: Fermi GBM detection
  57. SGR J1550-5418
  58. Ongoing activity of AXP/SGR 1E1547.0-5408
  59. GRB 090222: Fermi GBM detection
  60. GRB 090219: Fermi GBM detection
  61. GRB 090217: Suzaku WAM observation of the prompt emission
  62. Konus-Wind observation of GRB 090217
  63. IPN localization of GRB 090217
  64. GRB 090213: Fermi GBM detection
  65. GRB090217: Fermi-LAT Detection
  66. GRB 090217: Fermi GBM detection
  67. SGR activity seen by BAT during ICSP Ionospheric Events
  68. Detailed lightcurves of ICSP VLF Observation of SGR/AXP 1E1547.0-5408
  69. GRB 090207 - Fermi GBM Observations
  70. Fermi Gamma-ray Burst Monitor trigger 255729682 is not a GRB
  71. GRB 090129: Fermi GBM detection
  72. Fermi Gamma-ray Burst Monitor trigger 255541748 cannot be classified
  73. Fermi Gamma-ray Burst Monitor trigger 255342766 is not a GRB
  74. GRB 090202: Fermi GBM detection
  75. GRB 090131: Fermi GBM detection
  76. Konus-Wind observation of bright burst from AXP/SGR 1E1547.0-5408 on January 29
  77. Konus-Wind observation of AXP/SGR 1E1547.0-5408 bursting activity
  78. GRB 090126C: Fermi GBM detection
  79. GRB 090126B: Fermi GBM detection
  80. AXP 1E1547.0-5408: Suzaku WAM detections of the current activity
  81. AXP 1E1547.0-5408: Fermi GBM detection of additional bursts
  82. AXP 1E1547.0-5408: INTEGRAL SPI-ACS confirms activity increase
  83. AXP 1E1547.0-5408: Fermi GBM observations
  84. AXP 1E1547.0-5408 activity with SGR bursts
  85. GRB 090117B : Fermi GBM detection
  86. GRB 090117C - Fermi GRB Detection
  87. GRB 090117 - Fermi GBM Observations
  88. GRB 090112B: Fermi GBM Detection
  89. GRB 090113: Swift detection of a burst
  90. GRB 090112: Fermi GBM detection
  91. GRB 090109: Fermi GBM detection
  92. GRB 090108B: Fermi GBM detection
  93. GRB 090108: Fermi GBM Detection
  94. GRB090107B: Fermi GBM Detection
  95. Fermi/GBM detection of GRB 081226A
  96. Fermi/GBM detection of GRB 081225
  97. GRB 081231: Fermi GBM Detection
  98. GRB 081229: Fermi GBM detection
  99. GRB 081226B: Fermi GBM observation
  100. GRB 081226C: Fermi GBM detection

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