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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"

21772 results found.

  1. GRB 061222: Swift detection of a burst
  2. GRB 061218: TAROT La Silla observatory optical observations
  3. GRB 061217: TAROT Calern observatory optical observations
  4. GRB 061218: TORTOREM optical upper limits
  5. GRB 061218, Swift-BAT refined analysis
  6. GRB061217: VLT NIR observations
  7. GRB 061218, SMARTS optical/IR observations
  8. GRB 061218: REM prompt observations
  9. Swift triggers (#251863) on a possible burst
  10. GRB061217: Swift/UVOT refined analysis.
  11. GRB 061217: Magellan Observations
  12. GRB 061217: REM prompt observations
  13. GRB 061217: ROTSE-III Optical Limits
  14. GRB061210: Swift/UVOT observations
  15. GRB 061210: Swift XRT analysis - Possible counterparts
  16. GRB 061214(?): ROTSE-III Optical Limits
  17. GRB 061210: Suzaku WAM observation of the prompt emission
  18. GRB 061210: Gemini/GMOS Observations
  19. GRB 061126: Radio Observations
  20. GRB061210: Radio Observations
  21. GRB 061202: Suzaku WAM observation of the prompt emission
  22. GRB 061210, Swift-BAT refined analysis of the SHB
  23. Optical Afterglow observations of GRB 061126
  24. GRB 061201: UVOT Observations of a Fading Optical Afterglow
  25. GRB 061202: TORTOREM optical upper limits
  26. GRB 061201: VLT optical decay
  27. GRB 061201: SOAR Confirmation of Candidate Afterglow
  28. GRB061202: FRAM early follow-up limit
  29. GRB061202 optical limit by "Pi of the Sky"
  30. Konus-Wind observation of GRB 061201
  31. GRB061202: optical/NIR observations with REM
  32. GRB061202: Swift/UVOT Upper Limits
  33. GRB 061202, Swift-BAT refined analysis
  34. GRB 061202: Swift detection of a burst
  35. GRB 061201: VLT optical observations
  36. INT+WFC observations of GRB 061126
  37. GRB 061126: Early Super-LOTIS Observations
  38. RHESSI Spectrum of GRB061126
  39. GRB061126: Optical afterglow observations from MIRO
  40. GRB061126: Optical afterglow observations from MIRO
  41. GRB 061126 : SDSS Pre-Burst Observations
  42. GRB 061126: Swift/UVOT Observations
  43. GRB 061126: Early Detection of the IR Afterglow
  44. GRB 061126: Swift detection of a burst
  45. GRB 061122: Candidate Optical Afterglow
  46. GRB061122: Swift/UVOT Optical Observations
  47. GRB 061121: ART detection in Ic
  48. GRB061121: P60 Observations
  49. Radio detection of GRB 061121
  50. GRB061122: Swift-XRT position
  51. Konus-Wind observation of GRB 061122
  52. RHESSI Spectrum of GRB061121
  53. Konus-Wind and Konus-A observations of GRB 061121
  54. Swift-BAT trigger 239987 is not a GRB
  55. GRB 061121: Swift/UVOT Observations
  56. GRB 061121, Swift-BAT refined analysis
  57. GRB061121, optical observation
  58. GRB 061121: Optical observation at the KANATA 1.5m telescope
  59. GRB 061121: Swift detection of a bright burst with an optical counterpart
  60. GRB 060605: NIR Observations
  61. GRB 050915B: optical afterglow
  62. Swift/UVOT Upper Limits for GRB061110b
  63. Swift/UVOT Upper Limits for GRB061110a
  64. GRB 061110B, Swift-BAT refined analysis
  65. GRB061110B: Optical observations at Crni Vrh
  66. GRB 061110A, Swift-BAT refined analysis
  67. GRB 061110B: TAROT Calern observatory optical observations
  68. GRB 061110B: Swift detection of a burst
  69. GRB 061110: Candidate confirmed
  70. GRB 061110: ROTSE-III Optical Limits
  71. GRB 061110: Swift detection of a burst
  72. GRB061110A - Optical Non-detection
  73. GRB 061109: TAROT Calern observatory optical observations
  74. GRB 061027: TAROT La Silla observatory optical observations
  75. GRB 061028: Swift/XRT Astrometry Correction
  76. GRB 061102: Swift/UVOT Magnitude Upper Limits
  77. GRB061102B: Super-LOTIS observations
  78. GRB 061028: Optical R passband observations
  79. GRB 061102B: Swift detection of a possible burst
  80. GRB 061102: Swift detection of a burst
  81. GRB 061028: VLA Observation
  82. GRB 061004: Swift/XRT Astrometry Correction
  83. GRB 060801: Swift/XRT Astrometry Correction
  84. GRB 061028: Futher P200 Observations
  85. GRB 061028: P200 Observations
  86. GRB 061028: SARA upper limit
  87. GRB 061028: z band imaging
  88. GRB 061028: Swift/UVOT Observations
  89. GRB 061028, Swift-BAT refined analysis
  90. GRB 061028: TAROT Calern observatory optical observations
  91. GRB 061028: Swift detection of a burst
  92. GRB 061027, Swift refined analysis of a possible burst
  93. GRB 061027: Swift detection of a possible burst
  94. GRB061025: ROTSE-III Confirmation of Optical Counterpart
  95. GRB061025: Swift/UVOT observations
  96. GRB 061025: REM observations
  97. GRB 061025: ROTSE-III Optical Limits
  98. Konus-Wind observation of GRB 061021
  99. GRB 061021: Swift-XRT refined analysis
  100. GRB 061021: Swift/UVOT Observation

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