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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"

3762 results found.

  1. GRB 100111A: Swift detection of a burst with an optical afterglow
  2. GRB 091221: Skynet/PROMPT Detections
  3. GRB091208B: NOT optical observations
  4. GRB 091127: GAO 150cm telescope Optical Observation
  5. GRB 091127: Zadko Telescope Observations
  6. GRB 091128: Fermi GBM detection
  7. GRB 091127: optical observations
  8. GRB 091127 : GROND observations
  9. GRB 091031: Fermi LAT detection of a faint burst
  10. Fermi Gamma-ray Burst Monitor trigger 091028818 is not a GRB
  11. A mistake in testing a new function in Swift
  12. GRB 091024: Swift detection of a burst
  13. GRB 090926A: Late-time Gemini South Observations and Possible Jet Break
  14. Konus-RF observation of GRB 091018
  15. GRB091018: Magellan Echellette Observations
  16. GRB 091010: RXTE detection
  17. GRB 091003: Swift XRT analysis
  18. GRB 090927: Faulkes Telescope South Detection of the Optical Afterglow
  19. GRB 090915 Swift-BAT detection of a burst in ground analysis
  20. GRB 090912, Swift-BAT refined analysis
  21. GRB 090904B: GROND detection of the optical afterglow
  22. GRB 090902B: WSRT Radio Observation
  23. GRB 090828: Fermi GBM detection
  24. Fermi Gamma-ray Burst Monitor trigger 273123112 is not a GRB
  25. GRB 090820: Fermi GBM Detection of a bright burst.
  26. GRB 090817: aphotometry of USNO-B1.0 341-0096763
  27. GRB 090812: WIRO NIR upper limit
  28. GRB 090812: P60 Confirmation of Optical Afterglow
  29. GRB 090809B: Fermi GBM detection
  30. GRB 090726: optical observation
  31. GRB 090727: GRT Optical Observation
  32. GRB 090726: Swift-XRT Team refined analysis
  33. GRB 090718B: Fermi GBM detection
  34. GRB 090625B: Fermi GBM observation
  35. GRB 090625B: Faulkes Telescope South observations
  36. GRB 090618: Suzaku WAM observation of the prompt emission
  37. GRB 090621C: Fermi GBM detection
  38. Konus-Wind and Konus-RF observations of GRB 090618
  39. GRB 090618: Fermi GBM observation
  40. GRB 090618: AGILE observations
  41. GRB 090618: ROTSE-III Detection of Optical Counterpart
  42. GRB 090618: Swift detection of a bright burst with optical afterglow
  43. GRB 090531B, RIMOTS optical upper limits
  44. GRB 090528: Fermi GBM detection
  45. GRB 090529: Preliminary Swift/UVOT Upper Limit
  46. GRB 090529: Xinglong TNT optical observation
  47. GRB 090516C: Fermi GBM detection
  48. GRB 090515: Swift-BAT refined analysis
  49. GRB 090509: REM NIR afterglow
  50. GRB 090509: GROND afterglow candidate
  51. GRB 090323: optical observations
  52. GRB 090429A: GROND upper limits
  53. GRB 090428B: Fermi GBM detection
  54. GRB 090428: Fermi GBM detection
  55. GRB 090429B: RIMOTS optical upper limits
  56. IPN triangulation of very bright GRB 090427
  57. GRB 080408A: GAO 150cm telescope Optical Observation
  58. GRB 090418C: Fermi GBM Detection
  59. GRB 090412: Fermi GBM detection
  60. GRB 090411B: Fermi GBM detection
  61. GRB 090410: Swift detection of a burst
  62. GRB 090407: Swift detection of a burst
  63. GRB 090328B: Fermi GBM Detection
  64. GRB 090323: WSRT Radio Detection
  65. Fermi LAT and GBM detections of GRB090328
  66. IPN Triangulation of GRB090315 and Tupi Detection of Muon Increase
  67. Swift trigger 346250 is probably not a burst
  68. GRB 090309: Swift detection of a burst
  69. GRB 090307: Swift-XRT afterglow confirmation and analysis
  70. IPN localization of short GRB 090305C
  71. GRB 090228B: Fermi GBM detection
  72. GRB 090301B: Fermi GBM detection
  73. GRB 090228: Fermi GBM detection
  74. Ongoing activity of AXP/SGR 1E1547.0-5408
  75. GRB 090201: ROTSE-III Optical Limits
  76. Suzaku ToO Observation of AXP 1E 1547.0-5408
  77. AXP 1E1547.0-5408: Suzaku WAM detections of the current activity
  78. AXP 1E1547.0-5408: Fermi GBM detection of additional bursts
  79. GRB 090118: Possible burst detection from Swift-BAT slew data
  80. GRB 090113: LOAO Detection Limits in R, I, z, Y-band
  81. GRB 090108: Fermi GBM Detection
  82. GRB 090111: Swift detection of a burst
  83. GRB 090107B: ROTSE-III Optical Limits
  84. GRB 081223: Fermi GBM detection
  85. GRB081222 optical limit by "Pi of the Sky"
  86. IPN triangulation of bright GRB 081215A
  87. IPN localization of short hard GRB 081216
  88. GRB 081203B: Suzaku WAM observation of the prompt emission
  89. GRB 081128: optical observation in CrAO
  90. GRB 081128: optical observation
  91. GRB 081130B: Fermi GBM detection
  92. GRB 081128A: optical observations
  93. GRB 081128: Liverpool Telescope afterglow confirmation
  94. GRB081128: optical observations
  95. Konus-Wind observation of GRB 081126
  96. GRB 081122: Fermi GBM detection
  97. GRB081118 : optical upper limit
  98. GRB 081118: Swift-BAT refined analysis
  99. GRB 081109: Swift detection of a burst
  100. GRB 081028 - PAIRITEL NIR detection

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