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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: Swift-BAT refined analysis
  2. GRB 090308: Swift detection of a burst
  3. GRB 090306B: Possible XRT afterglow
  4. GRB 090307: Swift-XRT afterglow confirmation and analysis
  5. GRB 090307: Swift-BAT refined analysis of trigger 345551
  6. GRB 090306B: Burst detection from Swift-BAT slew data
  7. Swift Trigger 345551 is probably not a GRB
  8. Swift-BAT trigger 345396 is not a GRB
  9. IPN localization of short GRB 090305C
  10. Fermi GBM trigger 090305784 is not a GRB
  11. GRB 090306: Swift detection of a possible burst
  12. GRB 090305: Swift/UVOT Upper Limits
  13. GRB 090305: Swift-XRT refined analysis
  14. GRB 090305, Swift-BAT refined analysis
  15. GRB 090227A: Suzaku WAM observation of the prompt emission
  16. GRB 090305: Magellan confirmation of the optical afterglow
  17. GRB090305: GMOS-S Candidate Optical Afterglow
  18. GRB 090305: Swift detection of a short burst
  19. GRB 090303: Fermi GBM detection
  20. GRB 090304: Fermi GBM detection
  21. GRB 090301A: Suzaku WAM observation of the prompt emission
  22. Konus-RF catches first GRB and SGR bursts
  23. GRB 090228B: Fermi GBM detection
  24. Konus-Wind observation of bright short GRB 090227B
  25. IPN localization of short bright GRB 090227B
  26. Konus-Wind observation of GRB 090301A
  27. GRB 090301A: Swift-BAT refined analysis
  28. GRB 090301B: Fermi GBM detection
  29. GRB 090227B: Fermi GBM detection
  30. GRB 090301: Swift detection of a burst
  31. Swift_BAT_Lightcurve Notice for Trigger Number 344565 is not valid
  32. GRB 090228: Fermi GBM detection
  33. GRB 090227: Fermi GBM detection
  34. GRB 090206: Fermi GBM detection
  35. SGR J1550-5418
  36. GRB 081211B: Nearby cluster
  37. Ongoing activity of AXP/SGR 1E1547.0-5408
  38. GRB 090222: Fermi GBM detection
  39. GRB 090219: Fermi GBM detection
  40. Swift Restored
  41. Swift Trigger 343319 is not a GRB
  42. GRB 090217: Suzaku WAM observation of the prompt emission
  43. GRB090217: XRT analysis
  44. Konus-Wind observation of GRB 090217
  45. IPN localization of GRB 090217
  46. GRB 090213: Fermi GBM detection
  47. GRB090217: Fermi-LAT Detection
  48. GRB 090217: Fermi GBM detection
  49. SGR activity seen by BAT during ICSP Ionospheric Events
  50. Detailed lightcurves of ICSP VLF Observation of SGR/AXP 1E1547.0-5408
  51. GRB 090207 - Fermi GBM Observations
  52. Fermi Gamma-ray Burst Monitor trigger 255729682 is not a GRB
  53. GRB 090129: Fermi GBM detection
  54. VLA radio upper limit on GRB 090205
  55. GRB 090205: VLT optical decay
  56. Fermi Gamma-ray Burst Monitor trigger 255541748 cannot be classified
  57. GRB 090205: Swift/UVOT Upper Limits
  58. GRB 090205: VLT refined redshift
  59. GRB 090205: Swift-XRT refined analysis
  60. GRB 090205: Swift burst of interest
  61. GRB 090205: VLT spectroscopic redshift
  62. GRB 090205: GROND observations and photometric redshift estimate
  63. GRB 090205: VLT candidate afterglow
  64. GRB 090205: Swift-BAT refined analysis
  65. GRB 090205: Enhanced Swift-XRT position
  66. GRB 090205: Swift detection of a burst
  67. GRB 080319B: IceCube upper limit on high-energy neutrino flux
  68. GRB 090131: Suzaku WAM observation of the prompt emission
  69. ICSP VLF observation of the signatures of SGR/AXP 1E1547.0-5408 bursts
  70. GRB 090126A: Swift-XRT afterglow confirmation
  71. Fermi Gamma-ray Burst Monitor trigger 255342766 is not a GRB
  72. Konus-Wind observation of GRB 090201
  73. GRB 090202: Fermi GBM detection
  74. GRB 090131: Fermi GBM detection
  75. GRB 090201: Swift-XRT refined analysis
  76. GRB090201: Swift UVOT upper limits
  77. GRB 090201: object inside the enhanced XRT error circle
  78. GRB 090201: Enhanced Swift-XRT position
  79. GRB 090201: VLT NIR observations
  80. GRB 090201: Swift-BAT refined analysis
  81. GRB 090201: VLT afterglow candidate
  82. GRB 090201: Swift-XRT detection of the possible X-ray afterglow
  83. GRB090113: MAGIC telescope GeV observation
  84. GRB 090201: ROTSE-III Optical Limits
  85. GRB 090201: Swift detection of a burst
  86. GRB 090126A: Swift/UVOT Upper Limits
  87. Konus-Wind observation of bright burst from AXP/SGR 1E1547.0-5408 on January 29
  88. GRB 090129: Swift-BAT refined analysis
  89. GRB 090129: Swift detection of a burst
  90. IBAS Alert N. 5442 is not a GRB
  91. Suzaku ToO Observation of AXP 1E 1547.0-5408
  92. Konus-Wind observation of AXP/SGR 1E1547.0-5408 bursting activity
  93. AXP 1E1547.0-5408: RHESSI observations up to 400 keV
  94. GRB 090102: HST observations and host galaxy
  95. GRB 090126C: Fermi GBM detection
  96. GRB 090126A: Swift-XRT Refined Analysis
  97. GRB 090126B: Fermi GBM detection
  98. GRB 090126: SuperAGILE Localization of a Long GRB
  99. Konus-Wind detection of very bright SGR-like burst on January 25, 2009
  100. GRB 090118: no afterglow candidate

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