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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"

14323 results found.

  1. GRB 090323: TLS detection at 5 days, no break
  2. GRB 090327: Fermi GBM detection
  3. GRB 090323 TLS detection - still bright
  4. GRB 090323: UVOT Detection of Afterglow
  5. GRB 090323: GROND Detection of the Afterglow and Photo-z
  6. GRB 090320C: Fermi GBM Detection
  7. GRB 090320B: Fermi GBM detection.
  8. GRB 090319: Fermi GBM detection
  9. GRB 090320A: Fermi GBM detection
  10. GRB 090313: WSRT Radio Detection
  11. X-shooter observations of GRB 090313
  12. GRB 090313: VLT spectroscopy
  13. GRB090313: radio detection with the VLA
  14. IPN Triangulation of GRB090315 and Tupi Detection of Muon Increase
  15. GRB 090313: detection with CARMA in 3mm band
  16. Radio detection of GRB090313
  17. GRB 090313: TAROT La Silla observatory optical detection
  18. GRB 090313 optical observations
  19. GRB 090313: Swift/UVOT upper limits
  20. GRB 090313: Faulkes Telescope North observations
  21. GRB 090313: Swift detection of a burst
  22. GRB 090313: Swift detection of a burst
  23. GRB090310: Fermi GBM detection
  24. GRB090305B: Fermi GBM detection
  25. GRB 090309B: Fermi GBM detection
  26. GRB 090309: Swift detection of a burst
  27. GRB 090308B: Fermi GBM detection
  28. GRB 090307B: Fermi GBM detection
  29. GRB 090306C: Fermi GBM detection
  30. GRB 090308: Swift detection of a burst
  31. GRB 090306B: Burst detection from Swift-BAT slew data
  32. Swift Trigger 345551 is probably not a GRB
  33. GRB 090306: Swift detection of a possible burst
  34. GRB 090305: Swift-XRT refined analysis
  35. GRB 090305: Swift detection of a short burst
  36. GRB 090303: Fermi GBM detection
  37. GRB 090304: Fermi GBM detection
  38. GRB 090228B: Fermi GBM detection
  39. GRB 090301B: Fermi GBM detection
  40. GRB 090227B: Fermi GBM detection
  41. GRB 090301: Swift detection of a burst
  42. GRB 090228: Fermi GBM detection
  43. GRB 090227: Fermi GBM detection
  44. GRB 090206: Fermi GBM detection
  45. GRB 081211B: Nearby cluster
  46. GRB 090222: Fermi GBM detection
  47. GRB 090219: Fermi GBM detection
  48. GRB 090217: Suzaku WAM observation of the prompt emission
  49. GRB090217: XRT analysis
  50. GRB 090213: Fermi GBM detection
  51. GRB090217: Fermi-LAT Detection
  52. GRB 090217: Fermi GBM detection
  53. SGR activity seen by BAT during ICSP Ionospheric Events
  54. GRB 090129: Fermi GBM detection
  55. GRB 090205: GROND observations and photometric redshift estimate
  56. GRB 090205: Swift detection of a burst
  57. GRB 090202: Fermi GBM detection
  58. GRB 090131: Fermi GBM detection
  59. GRB 090201: VLT NIR observations
  60. GRB 090201: Swift-XRT detection of the possible X-ray afterglow
  61. GRB 090201: Swift detection of a burst
  62. GRB 090126A: Swift/UVOT Upper Limits
  63. GRB 090129: Swift detection of a burst
  64. GRB 090126C: Fermi GBM detection
  65. GRB 090126B: Fermi GBM detection
  66. Konus-Wind detection of very bright SGR-like burst on January 25, 2009
  67. GRB 090118: no afterglow candidate
  68. GRB 090123: GROND detection
  69. 1E1547.0-5408: Swift detection of dust halo
  70. GRB 090123: Swift/UVOT Observations
  71. GRB 090123: Swift detection of a burst
  72. AXP 1E1547.0-5408: Fermi GBM detection of additional bursts
  73. Trigger 340734: Swift detection of a possible short burst
  74. GRB 090118: KPNO 4m Detection of Candidate Afterglow
  75. GRB 090118: Possible burst detection from Swift-BAT slew data
  76. GRB 090117B : Fermi GBM detection
  77. GRB 090117C - Fermi GRB Detection
  78. GRB090117: Swift-XRT detection of a possible candidate afterglow
  79. GRB 090113: LOAO Detection Limits in R, I, z, Y-band
  80. GRB 090112B: Fermi GBM Detection
  81. GRB 090113: Swift detection of a burst
  82. GRB 090112: Fermi GBM detection
  83. GRB 090109: Fermi GBM detection
  84. GRB 090108B: Fermi GBM detection
  85. GRB 090108: Fermi GBM Detection
  86. GRB 090111: Swift detection of a burst
  87. GRB090107B: Fermi GBM Detection
  88. GRB 090107B: Swift-XRT detection of possible afterglow
  89. Fermi/GBM detection of GRB 081226A
  90. Fermi/GBM detection of GRB 081225
  91. GRB 090107: Swift detection of a burst
  92. GRB 081231: Fermi GBM Detection
  93. GRB 081229: Fermi GBM detection
  94. Swift UVOT observations of GRB 090102
  95. GRB 090102: Swift detection of a burst with an optical counterpart
  96. GRB 081230: Swift/UVOT Detection of an Optical Afterglow
  97. GRB 081230: ROTSE-III Detection of Optical Counterpart
  98. GRB 081230: Swift detection of a burst
  99. GRB 081226C: Fermi GBM detection
  100. VLA radio detection of GRB 081221

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