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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 090306B: Burst detection from Swift-BAT slew data
  2. Swift Trigger 345551 is probably not a GRB
  3. Swift-BAT trigger 345396 is not a GRB
  4. IPN localization of short GRB 090305C
  5. Fermi GBM trigger 090305784 is not a GRB
  6. GRB 090306: Swift detection of a possible burst
  7. GRB 090305: Swift/UVOT Upper Limits
  8. GRB 090305: Swift-XRT refined analysis
  9. GRB 090305, Swift-BAT refined analysis
  10. GRB 090227A: Suzaku WAM observation of the prompt emission
  11. GRB 090305: Magellan confirmation of the optical afterglow
  12. GRB090305: GMOS-S Candidate Optical Afterglow
  13. GRB 090305: Swift detection of a short burst
  14. GRB 090303: Fermi GBM detection
  15. GRB 090304: Fermi GBM detection
  16. GRB 090301A: Suzaku WAM observation of the prompt emission
  17. Konus-RF catches first GRB and SGR bursts
  18. GRB 090228B: Fermi GBM detection
  19. Konus-Wind observation of bright short GRB 090227B
  20. IPN localization of short bright GRB 090227B
  21. Konus-Wind observation of GRB 090301A
  22. GRB 090301A: Swift-BAT refined analysis
  23. GRB 090301B: Fermi GBM detection
  24. GRB 090227B: Fermi GBM detection
  25. GRB 090301: Swift detection of a burst
  26. Swift_BAT_Lightcurve Notice for Trigger Number 344565 is not valid
  27. GRB 090228: Fermi GBM detection
  28. GRB 090227: Fermi GBM detection
  29. GRB 090206: Fermi GBM detection
  30. SGR J1550-5418
  31. GRB 081211B: Nearby cluster
  32. Ongoing activity of AXP/SGR 1E1547.0-5408
  33. GRB 090222: Fermi GBM detection
  34. GRB 090219: Fermi GBM detection
  35. Swift Restored
  36. Swift Trigger 343319 is not a GRB
  37. GRB 090217: Suzaku WAM observation of the prompt emission
  38. GRB090217: XRT analysis
  39. Konus-Wind observation of GRB 090217
  40. IPN localization of GRB 090217
  41. GRB 090213: Fermi GBM detection
  42. GRB090217: Fermi-LAT Detection
  43. GRB 090217: Fermi GBM detection
  44. SGR activity seen by BAT during ICSP Ionospheric Events
  45. Detailed lightcurves of ICSP VLF Observation of SGR/AXP 1E1547.0-5408
  46. GRB 090207 - Fermi GBM Observations
  47. Fermi Gamma-ray Burst Monitor trigger 255729682 is not a GRB
  48. GRB 090129: Fermi GBM detection
  49. VLA radio upper limit on GRB 090205
  50. GRB 090205: VLT optical decay
  51. Fermi Gamma-ray Burst Monitor trigger 255541748 cannot be classified
  52. GRB 090205: Swift/UVOT Upper Limits
  53. GRB 090205: VLT refined redshift
  54. GRB 090205: Swift-XRT refined analysis
  55. GRB 090205: Swift burst of interest
  56. GRB 090205: VLT spectroscopic redshift
  57. GRB 090205: GROND observations and photometric redshift estimate
  58. GRB 090205: VLT candidate afterglow
  59. GRB 090205: Swift-BAT refined analysis
  60. GRB 090205: Enhanced Swift-XRT position
  61. GRB 090205: Swift detection of a burst
  62. GRB 080319B: IceCube upper limit on high-energy neutrino flux
  63. GRB 090131: Suzaku WAM observation of the prompt emission
  64. ICSP VLF observation of the signatures of SGR/AXP 1E1547.0-5408 bursts
  65. GRB 090126A: Swift-XRT afterglow confirmation
  66. Fermi Gamma-ray Burst Monitor trigger 255342766 is not a GRB
  67. Konus-Wind observation of GRB 090201
  68. GRB 090202: Fermi GBM detection
  69. GRB 090131: Fermi GBM detection
  70. GRB 090201: Swift-XRT refined analysis
  71. GRB090201: Swift UVOT upper limits
  72. GRB 090201: object inside the enhanced XRT error circle
  73. GRB 090201: Enhanced Swift-XRT position
  74. GRB 090201: VLT NIR observations
  75. GRB 090201: Swift-BAT refined analysis
  76. GRB 090201: VLT afterglow candidate
  77. GRB 090201: Swift-XRT detection of the possible X-ray afterglow
  78. GRB090113: MAGIC telescope GeV observation
  79. GRB 090201: ROTSE-III Optical Limits
  80. GRB 090201: Swift detection of a burst
  81. GRB 090126A: Swift/UVOT Upper Limits
  82. Konus-Wind observation of bright burst from AXP/SGR 1E1547.0-5408 on January 29
  83. GRB 090129: Swift-BAT refined analysis
  84. GRB 090129: Swift detection of a burst
  85. IBAS Alert N. 5442 is not a GRB
  86. Suzaku ToO Observation of AXP 1E 1547.0-5408
  87. Konus-Wind observation of AXP/SGR 1E1547.0-5408 bursting activity
  88. AXP 1E1547.0-5408: RHESSI observations up to 400 keV
  89. GRB 090102: HST observations and host galaxy
  90. GRB 090126C: Fermi GBM detection
  91. GRB 090126A: Swift-XRT Refined Analysis
  92. GRB 090126B: Fermi GBM detection
  93. GRB 090126: SuperAGILE Localization of a Long GRB
  94. Konus-Wind detection of very bright SGR-like burst on January 25, 2009
  95. GRB 090118: no afterglow candidate
  96. GRB 090123: GROND detection
  97. 1E1547.0-5408: Swift detection of dust halo
  98. GRB 090123: Swift XRT refined analysis
  99. GRB 090123: Swift/UVOT Observations
  100. AXP 1E1547.0-5408: Suzaku WAM detections of the current activity

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