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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"

41675 results found.

  1. GRB 061126: a GRB detected off-axis by INTEGRAL
  2. GRB 061202: Suzaku WAM observation of the prompt emission
  3. GRB 061210: Swift-BAT detection of a short burst
  4. Optical Afterglow observations of GRB 061126
  5. GRB061126: optical observations
  6. GRB 060926: MASTER: discovery of the optical flare
  7. Corrections for Swift/UVOT Exposure Times for GRBs 061110B and 061121
  8. GRB 061201: UVOT Observations of a Fading Optical Afterglow
  9. GRB 061202: TORTOREM optical upper limits
  10. GRB 061201: VLT optical decay
  11. GRB 061201: SOAR Confirmation of Candidate Afterglow
  12. GRB061126 : NMSU 1.0m observations
  13. GRB 061202: Swift XRT refined analysis
  14. GRB061202: FRAM early follow-up limit
  15. GRB061202 optical limit by "Pi of the Sky"
  16. Konus-Wind observation of GRB 061201
  17. GRB061202: optical/NIR observations with REM
  18. GRB061202: Swift/UVOT Upper Limits
  19. GRB 061202, Swift-BAT refined analysis
  20. GRB 061202: Swift detection of a burst
  21. GRB 061201: Swift XRT Team refined analysis
  22. GRB 061201: VLT optical observations
  23. GRB 061201: Initial UVOT Observations
  24. GRB 061201, Swift-BAT refined analysis of the SHB
  25. GRB 061201: Swift detection of a short hard burst
  26. GRB 061201: Coincidence with a Galaxy Cluster
  27. GRB 061122: GETS observation
  28. GRB 061121, SMARTS optical/IR observations
  29. INT+WFC observations of GRB 061126
  30. GRB 061126: Possible Jet Break
  31. GRB 061121: Second Epoch ATCA Radio Observations
  32. GRB 061126: RAPTOR Optical Detection During Gamma-Ray Emission
  33. Swift XRT on-board boresight update
  34. GRB 061121: ATCA & WSRT Radio Observations
  35. GRB061121: optical observations
  36. GRB 061126: Early Super-LOTIS Observations
  37. GRB 061126: optical observation
  38. RHESSI Spectrum of GRB061126
  39. GRB 061126: Tautenburg afterglow observations
  40. GRB061126: Optical afterglow observations from MIRO
  41. GRB061126: Optical afterglow observations from MIRO
  42. GRB 061126 : SDSS Pre-Burst Observations
  43. GRB 061126: Swift-XRT refined analysis
  44. GRB 061126: Swift/UVOT Observations
  45. GRB 061126: SARA Observations
  46. GRB 061126: Early Detection of the IR Afterglow
  47. GRB 061126: Faulkes Telescope North Optical Observations
  48. GRB 061126: Swift/UVOT Afterglow Detection
  49. GRB 061126: XRT position
  50. GRB 061126: Swift detection of a burst
  51. GRB 061121: MDM Continued Monitoring
  52. GRB 061121: MDM Continuing Optical Decay
  53. GRB061121: optical observations
  54. GRB 061122: Candidate Optical Afterglow
  55. GRB 061121: Ep,i - Eiso correlation
  56. GRB 061121: MDM Optical Decay
  57. GRB061122: Swift/UVOT Optical Observations
  58. GRB061121: P60 Observations
  59. Radio detection of GRB 061121
  60. GRB061122: Swift-XRT position
  61. Konus-Wind observation of GRB 061122
  62. GRB 061121: MDM Optical Observations
  63. GRB 061121 declared "Burst of Interest" by Swift team
  64. RHESSI Spectrum of GRB061121
  65. Konus-Wind and Konus-A observations of GRB 061121
  66. INTEGRAL results on GRB 061122
  67. Swift-BAT trigger 239987 is not a GRB
  68. GRB 061122A: a long GRB detected by INTEGRAL
  69. GRB 061121: Swift/UVOT Observations
  70. GRB 061121: Swift-XRT Team Refined Analysis
  71. GRB 061121, Swift-BAT refined analysis
  72. GRB 061121 : Planned XMM-Newton observation
  73. GRB 061121: Optical observation at the KANATA 1.5m telescope
  74. GRB 061121: Faulkes Telescope North Optical Observation
  75. GRB061121: Spectroscopic Redshift
  76. GRB061121: Keck spectroscopic observations
  77. GRB 061121: Swift detection of a bright burst with an optical counterpart
  78. GRB 060605: NIR Observations
  79. GRB 050915B: optical afterglow
  80. GRB 060111B: Swift UVOT Refined Magnitudes
  81. Swift-BAT triggers 238544 and 238546 are not GRBs
  82. GRB 061110A: refined R-band analysis
  83. GRB 061110B: NIR Observations
  84. Swift TOO observations of GRB061110A
  85. GRB 061110A - VLT tentative redshift
  86. GRB 061110B: Swift XRT refined analysis
  87. GRB 061110B, Swift-BAT refined analysis
  88. GRB 061110B: VLT redshift
  89. GRB061110B: Optical observations at Crni Vrh
  90. GRB 061110B: NOT optical observations
  91. GRB 061110A: Swift XRT refined analysis
  92. GRB 061110B: Swift/XRT position
  93. GRB 061110A, Swift-BAT refined analysis
  94. GRB 061110B: TAROT Calern observatory optical observations
  95. GRB 061110B: Swift detection of a burst
  96. GRB 061110: NOT observations
  97. GRB 061110: Candidate confirmed
  98. GRB 061110 : Optical afterglow candidate
  99. GRB 061110: ROTSE-III Optical Limits
  100. GRB 061110: Swift detection of a burst

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