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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"
  1. GRB 090309: Swift detection of a burst
  2. GRB 090308B: Fermi GBM detection
  3. GRB 090308: Swift/UVOT Upper Limits
  4. GRB 090307B: Fermi GBM detection
  5. GRB 090306C: Fermi GBM detection
  6. GRB 090307: GROND Upper Limits
  7. GRB 090306B: GROND Upper Limits
  8. GRB 090305C: Suzaku WAM observation of the prompt emission
  9. GRB 090308: Swift-XRT refined analysis
  10. Radio observation of GRB 090201 with ATCA
  11. Radio observation of GRB 090117 with ATCA
  12. Radio observation of GRB 081226b with ATCA
  13. Radio observation of GRB 081226a with ATCA
  14. Radio observation of GRB 081007 with ATCA
  15. ATCA observation of SGR J1550-5418
  16. GRB 090308: Swift-BAT refined analysis
  17. GRB 090308: Swift detection of a burst
  18. GRB 090306B: Possible XRT afterglow
  19. GRB 090307: Swift-XRT afterglow confirmation and analysis
  20. GRB 090307: Swift-BAT refined analysis of trigger 345551
  21. GRB 090306B: Burst detection from Swift-BAT slew data
  22. Swift Trigger 345551 is probably not a GRB
  23. Swift-BAT trigger 345396 is not a GRB
  24. IPN localization of short GRB 090305C
  25. Fermi GBM trigger 090305784 is not a GRB
  26. GRB 090306: Swift detection of a possible burst
  27. GRB 090305: Swift/UVOT Upper Limits
  28. GRB 090305: Swift-XRT refined analysis
  29. GRB 090305, Swift-BAT refined analysis
  30. GRB 090227A: Suzaku WAM observation of the prompt emission
  31. GRB 090305: Magellan confirmation of the optical afterglow
  32. GRB090305: GMOS-S Candidate Optical Afterglow
  33. GRB 090305: Swift detection of a short burst
  34. GRB 090303: Fermi GBM detection
  35. GRB 090304: Fermi GBM detection
  36. GRB 090301A: Suzaku WAM observation of the prompt emission
  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. Konus-Wind observation of GRB 090301A
  42. GRB 090301A: Swift-BAT refined analysis
  43. GRB 090301B: Fermi GBM detection
  44. GRB 090227B: Fermi GBM detection
  45. GRB 090301: Swift detection of a burst
  46. Swift_BAT_Lightcurve Notice for Trigger Number 344565 is not valid
  47. GRB 090228: Fermi GBM detection
  48. GRB 090227: Fermi GBM detection
  49. GRB 090206: Fermi GBM detection
  50. SGR J1550-5418
  51. GRB 081211B: Nearby cluster
  52. Ongoing activity of AXP/SGR 1E1547.0-5408
  53. GRB 090222: Fermi GBM detection
  54. GRB 090219: Fermi GBM detection
  55. Swift Restored
  56. Swift Trigger 343319 is not a GRB
  57. GRB 090217: Suzaku WAM observation of the prompt emission
  58. GRB090217: XRT analysis
  59. Konus-Wind observation of GRB 090217
  60. IPN localization of GRB 090217
  61. GRB 090213: Fermi GBM detection
  62. GRB090217: Fermi-LAT Detection
  63. GRB 090217: Fermi GBM detection
  64. SGR activity seen by BAT during ICSP Ionospheric Events
  65. Detailed lightcurves of ICSP VLF Observation of SGR/AXP 1E1547.0-5408
  66. GRB 090207 - Fermi GBM Observations
  67. Fermi Gamma-ray Burst Monitor trigger 255729682 is not a GRB
  68. GRB 090129: Fermi GBM detection
  69. VLA radio upper limit on GRB 090205
  70. GRB 090205: VLT optical decay
  71. Fermi Gamma-ray Burst Monitor trigger 255541748 cannot be classified
  72. GRB 090205: Swift/UVOT Upper Limits
  73. GRB 090205: VLT refined redshift
  74. GRB 090205: Swift-XRT refined analysis
  75. GRB 090205: Swift burst of interest
  76. GRB 090205: VLT spectroscopic redshift
  77. GRB 090205: GROND observations and photometric redshift estimate
  78. GRB 090205: VLT candidate afterglow
  79. GRB 090205: Swift-BAT refined analysis
  80. GRB 090205: Enhanced Swift-XRT position
  81. GRB 090205: Swift detection of a burst
  82. GRB 080319B: IceCube upper limit on high-energy neutrino flux
  83. GRB 090131: Suzaku WAM observation of the prompt emission
  84. ICSP VLF observation of the signatures of SGR/AXP 1E1547.0-5408 bursts
  85. GRB 090126A: Swift-XRT afterglow confirmation
  86. Fermi Gamma-ray Burst Monitor trigger 255342766 is not a GRB
  87. Konus-Wind observation of GRB 090201
  88. GRB 090202: Fermi GBM detection
  89. GRB 090131: Fermi GBM detection
  90. GRB 090201: Swift-XRT refined analysis
  91. GRB090201: Swift UVOT upper limits
  92. GRB 090201: object inside the enhanced XRT error circle
  93. GRB 090201: Enhanced Swift-XRT position
  94. GRB 090201: VLT NIR observations
  95. GRB 090201: Swift-BAT refined analysis
  96. GRB 090201: VLT afterglow candidate
  97. GRB 090201: Swift-XRT detection of the possible X-ray afterglow
  98. GRB090113: MAGIC telescope GeV observation
  99. GRB 090201: ROTSE-III Optical Limits
  100. GRB 090201: Swift detection of a burst

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