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

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