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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"

11522 results found.

  1. GRB 090328: GROND Detection of the Optical/NIR Afterglow
  2. GRB 090328: Gemini South Redshift
  3. GRB 090328: Swift XRT refined analysis
  4. Konus-Wind observation of GRB 090328
  5. GRB 090328: IPN Triangulation
  6. GRB 090328: Swift UVOT observations
  7. Fermi LAT and GBM detections of GRB090328
  8. GRB 090323: Radio afterglow detection
  9. GRB 090323: TLS detection at 5 days, no break
  10. GRB 090327: Fermi GBM detection
  11. GRB 090323: Faulkes Telescope South Observations
  12. GRB 090320B: MASTER-Net prompt optical observations
  13. GRB 090323: Fermi GBM Spectral Analysis
  14. GRB 090323 TLS detection - still bright
  15. GRB 090323: UVOT Detection of Afterglow
  16. GRB 090323: Swift-XRT refined analysis
  17. Konus-Wind observation of GRB 090323
  18. GRB 090323: GROND Detection of the Afterglow and Photo-z
  19. SGR J1550-5418: two Fermi GBM triggers on March 22
  20. GRB 090323: Possible XRT Counterpart
  21. IPN triangulation of GRB090323
  22. GRB 090320C: Fermi GBM Detection
  23. Fermi GBM and LAT detections of GRB 090323
  24. GRB 090320B: Fermi GBM detection.
  25. GRB 090319: Fermi GBM detection
  26. GRB 090320A: Fermi GBM detection
  27. GRB090305B: MASTER-net prompt optical short burst observations
  28. GRB090310: Fermi GBM detection
  29. GRB090305B: Fermi GBM detection
  30. GRB 090309B: Fermi GBM detection
  31. GRB 090308B: Fermi GBM detection
  32. GRB 090307B: Fermi GBM detection
  33. GRB 090306C: Fermi GBM detection
  34. Fermi GBM trigger 090305784 is not a GRB
  35. GRB 090303: Fermi GBM detection
  36. GRB 090304: Fermi GBM detection
  37. Konus-RF catches first GRB and SGR bursts
  38. GRB 090228B: Fermi GBM detection
  39. Konus-Wind observation of bright short GRB 090227B
  40. IPN localization of short bright GRB 090227B
  41. GRB 090301B: Fermi GBM detection
  42. GRB 090227B: Fermi GBM detection
  43. GRB 090228: Fermi GBM detection
  44. GRB 090227: Fermi GBM detection
  45. GRB 090206: Fermi GBM detection
  46. SGR J1550-5418
  47. Ongoing activity of AXP/SGR 1E1547.0-5408
  48. GRB 090222: Fermi GBM detection
  49. GRB 090219: Fermi GBM detection
  50. GRB 090217: Suzaku WAM observation of the prompt emission
  51. Konus-Wind observation of GRB 090217
  52. IPN localization of GRB 090217
  53. GRB 090213: Fermi GBM detection
  54. GRB090217: Fermi-LAT Detection
  55. GRB 090217: Fermi GBM detection
  56. SGR activity seen by BAT during ICSP Ionospheric Events
  57. Detailed lightcurves of ICSP VLF Observation of SGR/AXP 1E1547.0-5408
  58. GRB 090207 - Fermi GBM Observations
  59. Fermi Gamma-ray Burst Monitor trigger 255729682 is not a GRB
  60. GRB 090129: Fermi GBM detection
  61. Fermi Gamma-ray Burst Monitor trigger 255541748 cannot be classified
  62. Fermi Gamma-ray Burst Monitor trigger 255342766 is not a GRB
  63. GRB 090202: Fermi GBM detection
  64. GRB 090131: Fermi GBM detection
  65. Konus-Wind observation of bright burst from AXP/SGR 1E1547.0-5408 on January 29
  66. Konus-Wind observation of AXP/SGR 1E1547.0-5408 bursting activity
  67. GRB 090126C: Fermi GBM detection
  68. GRB 090126B: Fermi GBM detection
  69. AXP 1E1547.0-5408: Suzaku WAM detections of the current activity
  70. AXP 1E1547.0-5408: Fermi GBM detection of additional bursts
  71. AXP 1E1547.0-5408: INTEGRAL SPI-ACS confirms activity increase
  72. AXP 1E1547.0-5408: Fermi GBM observations
  73. AXP 1E1547.0-5408 activity with SGR bursts
  74. GRB 090117B : Fermi GBM detection
  75. GRB 090117C - Fermi GRB Detection
  76. GRB 090117 - Fermi GBM Observations
  77. GRB 090112B: Fermi GBM Detection
  78. GRB 090113: Swift detection of a burst
  79. GRB 090112: Fermi GBM detection
  80. GRB 090109: Fermi GBM detection
  81. GRB 090108B: Fermi GBM detection
  82. GRB 090108: Fermi GBM Detection
  83. GRB090107B: Fermi GBM Detection
  84. Fermi/GBM detection of GRB 081226A
  85. Fermi/GBM detection of GRB 081225
  86. GRB 081231: Fermi GBM Detection
  87. GRB 081229: Fermi GBM detection
  88. GRB 081226B: Fermi GBM observation
  89. GRB 081226C: Fermi GBM detection
  90. GRB 081224: Suzaku WAM observation of the prompt emission
  91. GRB 081224: Swift-XRT observation
  92. GRB 081224: Fermi GBM Detection & LAT Localization
  93. GRB 081223: Fermi GBM detection
  94. GRB 081221: GROND observations
  95. GRB 081222: Fermi GBM observation
  96. Fermi Gamma-ray Burst Monitor trigger 251687595 reclassification
  97. GRB 081204C: Fermi GBM detection
  98. Konus-Wind observation of very bright GRB 081215A
  99. GRB081221: Fermi GBM observation
  100. IPN triangulation of bright GRB 081215A

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