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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 061213: MASTER-VWF-Kislovodsk OT candidate retraction
  2. GRB 061213: MASTER-VWF-Kislovodsk optical candidate
  3. GRB 061213: MASTER-VWF-Kislovodsk observations
  4. GRB 061210: Gemini/GMOS Observations
  5. GRB 061126: Radio Observations
  6. GRB061210: Radio Observations
  7. GRB061201, VLT optical decay: correction
  8. GRB 061126: a GRB detected off-axis by INTEGRAL
  9. GRB 061202: Suzaku WAM observation of the prompt emission
  10. GRB 061210: MDM Observation
  11. GRB 061210, Swift-BAT refined analysis of the SHB
  12. GRB 061210: Swift-BAT detection of a short burst
  13. Optical Afterglow observations of GRB 061126
  14. GRB061126: optical observations
  15. GRB 060926: MASTER: discovery of the optical flare
  16. GRB061126: update on the Swift-XRT afterglow light curve
  17. Corrections for Swift/UVOT Exposure Times for GRBs 061110B and 061121
  18. GRB 061201: UVOT Observations of a Fading Optical Afterglow
  19. GRB 061202: TORTOREM optical upper limits
  20. GRB 061201: VLT optical decay
  21. GRB 061201: SOAR Confirmation of Candidate Afterglow
  22. GRB061126 : NMSU 1.0m observations
  23. GRB 061202: Swift XRT refined analysis
  24. GRB061202: FRAM early follow-up limit
  25. GRB061202 optical limit by "Pi of the Sky"
  26. Konus-Wind observation of GRB 061201
  27. GRB061202: optical/NIR observations with REM
  28. GRB061202: Swift/UVOT Upper Limits
  29. GRB 061202, Swift-BAT refined analysis
  30. GRB 061202: Swift detection of a burst
  31. GRB 061201: Swift XRT Team refined analysis
  32. GRB 061201: VLT optical observations
  33. GRB 061201: Initial UVOT Observations
  34. GRB 061201, Swift-BAT refined analysis of the SHB
  35. GRB 061201: Swift detection of a short hard burst
  36. GRB 061201: Coincidence with a Galaxy Cluster
  37. GRB 061122: GETS observation
  38. GRB 061121, SMARTS optical/IR observations
  39. GRB 061121: flattening of the decay
  40. INT+WFC observations of GRB 061126
  41. GRB 061126: Possible Jet Break
  42. GRB 061121: Second Epoch ATCA Radio Observations
  43. GRB 061126: RAPTOR Optical Detection During Gamma-Ray Emission
  44. Swift XRT on-board boresight update
  45. GRB 061121: ATCA & WSRT Radio Observations
  46. GRB061121: optical observations
  47. GRB 061126: Early Super-LOTIS Observations
  48. GRB 061126: optical observation
  49. RHESSI Spectrum of GRB061126
  50. GRB 061126: Tautenburg afterglow observations
  51. GRB061126: Optical afterglow observations from MIRO
  52. GRB061126: Optical afterglow observations from MIRO
  53. GRB 061126 : SDSS Pre-Burst Observations
  54. GRB 061126: Swift-XRT refined analysis
  55. GRB 061126: Swift/UVOT Observations
  56. GRB 061126, Swift-BAT refined analysis
  57. GRB 061126: SARA Observations
  58. GRB 061126: Early Detection of the IR Afterglow
  59. GRB 061126: Faulkes Telescope North Optical Observations
  60. GRB 061126: Swift/UVOT Afterglow Detection
  61. GRB 061126: XRT position
  62. GRB 061126: Swift detection of a burst
  63. GRB 061121: MDM Continued Monitoring
  64. GRB 061122: Confirmation of X-ray/Optical Afterglow
  65. GRB 061121: MDM Continuing Optical Decay
  66. GRB061121: optical observations
  67. GRB 061122: Candidate Optical Afterglow
  68. GRB 061121: Ep,i - Eiso correlation
  69. GRB 061121: MDM Optical Decay
  70. GRB061122: Swift/UVOT Optical Observations
  71. GRB 061121: ART detection in Ic
  72. GRB061121: P60 Observations
  73. Radio detection of GRB 061121
  74. GRB061122: Swift-XRT position
  75. Konus-Wind observation of GRB 061122
  76. GRB 061121: MDM Optical Observations
  77. GRB 061121 declared "Burst of Interest" by Swift team
  78. RHESSI Spectrum of GRB061121
  79. Konus-Wind and Konus-A observations of GRB 061121
  80. INTEGRAL results on GRB 061122
  81. Swift-BAT trigger 239987 is not a GRB
  82. GRB 061122A: a long GRB detected by INTEGRAL
  83. GRB 061121: Swift/UVOT Observations
  84. GRB 061121: Swift-XRT Team Refined Analysis
  85. GRB 061121, Swift-BAT refined analysis
  86. GRB061121, optical observation
  87. GRB 061121 : Planned XMM-Newton observation
  88. GRB 061121: Optical observation at the KANATA 1.5m telescope
  89. GRB 061121: Faulkes Telescope North Optical Observation
  90. GRB061121: Spectroscopic Redshift
  91. GRB061121: Keck spectroscopic observations
  92. GRB 061121: ROTSE-III Confirmation of Optical Counterpart
  93. GRB 061121: Swift detection of a bright burst with an optical counterpart
  94. GRB 060605: NIR Observations
  95. GRB 050915B: optical afterglow
  96. GRB 060111B: Swift UVOT Refined Magnitudes
  97. Swift-BAT triggers 238544 and 238546 are not GRBs
  98. GRB061110A: Correction to GCN5817
  99. GRB 061110A: refined R-band analysis
  100. GRB 061110B: NIR Observations

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