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

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