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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"

11556 results found.

  1. GRB 090426C: Fermi GBM detection
  2. GRB 090426B: Fermi GBM detection/observation
  3. GRB 090428B: Fermi GBM detection
  4. GRB 090428: Fermi GBM detection
  5. GRB 090425: Fermi GBM detection
  6. GRB 090424: MASTER-Net prompt optical limit
  7. GRB 090423: Fermi GBM observation (correction of isotropic equivalent energy)
  8. GRB 090423: Swift/BAT spectral lag results
  9. GRB 090423: energetic, luminosity and jet break
  10. GRB 090424: Fermi GBM Observation
  11. GRB 090423: Fermi GBM observation
  12. GRB 090422: Fermi GBM observation
  13. GRB 090418C: Fermi GBM Detection
  14. GRB 090411B: Suzaku WAM observation of the prompt emission
  15. GRB 090411A: Suzaku WAM observation of the prompt emission
  16. GRB 090412: Fermi GBM detection
  17. GRB 090411B: Fermi GBM detection
  18. GRB 090411A: Fermi GBM detection
  19. Fermi GBM trigger 261106787 is not a GRB
  20. GRB 090409: Fermi GBM detection
  21. Fermi GBM Detection of a weak source
  22. GRB 090405: Fermi GBM Detection
  23. GRB 090403: Fermi GBM detection
  24. Fermi Gamma-ray Burst Monitor trigger 260428446 is not a GRB
  25. GRB 090328: Fermi-LAT refined analysis
  26. GRB 090331: Fermi GBM detection
  27. GRB 090328B: MASTER-Irkutsk prompt optical short burst observations
  28. GRB 090323: Further TLS detections - a break?
  29. GRB 090328: Radio afterglow detection
  30. GRB 090326: Fermi GBM detection
  31. GRB 090328: BOOTES-3 optical observations
  32. GRB 090328: Fermi GBM Spectral Analysis
  33. GRB 090328B: Fermi GBM Detection
  34. GRB 090330: Fermi GBM detection
  35. GRB 090328: GROND Detection of the Optical/NIR Afterglow
  36. GRB 090328: Gemini South Redshift
  37. GRB 090328: Swift XRT refined analysis
  38. Konus-Wind observation of GRB 090328
  39. GRB 090328: IPN Triangulation
  40. GRB 090328: Swift UVOT observations
  41. Fermi LAT and GBM detections of GRB090328
  42. GRB 090323: Radio afterglow detection
  43. GRB 090323: TLS detection at 5 days, no break
  44. GRB 090327: Fermi GBM detection
  45. GRB 090323: Faulkes Telescope South Observations
  46. GRB 090320B: MASTER-Net prompt optical observations
  47. GRB 090323: Fermi GBM Spectral Analysis
  48. GRB 090323 TLS detection - still bright
  49. GRB 090323: UVOT Detection of Afterglow
  50. GRB 090323: Swift-XRT refined analysis
  51. Konus-Wind observation of GRB 090323
  52. GRB 090323: GROND Detection of the Afterglow and Photo-z
  53. SGR J1550-5418: two Fermi GBM triggers on March 22
  54. GRB 090323: Possible XRT Counterpart
  55. IPN triangulation of GRB090323
  56. GRB 090320C: Fermi GBM Detection
  57. Fermi GBM and LAT detections of GRB 090323
  58. GRB 090320B: Fermi GBM detection.
  59. GRB 090319: Fermi GBM detection
  60. GRB 090320A: Fermi GBM detection
  61. GRB090305B: MASTER-net prompt optical short burst observations
  62. GRB090310: Fermi GBM detection
  63. GRB090305B: Fermi GBM detection
  64. GRB 090309B: Fermi GBM detection
  65. GRB 090308B: Fermi GBM detection
  66. GRB 090307B: Fermi GBM detection
  67. GRB 090306C: Fermi GBM detection
  68. Fermi GBM trigger 090305784 is not a GRB
  69. GRB 090303: Fermi GBM detection
  70. GRB 090304: Fermi GBM detection
  71. Konus-RF catches first GRB and SGR bursts
  72. GRB 090228B: Fermi GBM detection
  73. Konus-Wind observation of bright short GRB 090227B
  74. IPN localization of short bright GRB 090227B
  75. GRB 090301B: Fermi GBM detection
  76. GRB 090227B: Fermi GBM detection
  77. GRB 090228: Fermi GBM detection
  78. GRB 090227: Fermi GBM detection
  79. GRB 090206: Fermi GBM detection
  80. SGR J1550-5418
  81. Ongoing activity of AXP/SGR 1E1547.0-5408
  82. GRB 090222: Fermi GBM detection
  83. GRB 090219: Fermi GBM detection
  84. GRB 090217: Suzaku WAM observation of the prompt emission
  85. Konus-Wind observation of GRB 090217
  86. IPN localization of GRB 090217
  87. GRB 090213: Fermi GBM detection
  88. GRB090217: Fermi-LAT Detection
  89. GRB 090217: Fermi GBM detection
  90. SGR activity seen by BAT during ICSP Ionospheric Events
  91. Detailed lightcurves of ICSP VLF Observation of SGR/AXP 1E1547.0-5408
  92. GRB 090207 - Fermi GBM Observations
  93. Fermi Gamma-ray Burst Monitor trigger 255729682 is not a GRB
  94. GRB 090129: Fermi GBM detection
  95. Fermi Gamma-ray Burst Monitor trigger 255541748 cannot be classified
  96. Fermi Gamma-ray Burst Monitor trigger 255342766 is not a GRB
  97. GRB 090202: Fermi GBM detection
  98. GRB 090131: Fermi GBM detection
  99. Konus-Wind observation of bright burst from AXP/SGR 1E1547.0-5408 on January 29
  100. Konus-Wind observation of AXP/SGR 1E1547.0-5408 bursting activity

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