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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"

26383 results found.

  1. GRB061217 - Swift/XRT refined analysis
  2. GRB 061217, Swift-BAT refined analysis
  3. GRB 061217: Magellan Observations
  4. GRB 061217: REM prompt observations
  5. GRB 061217: ROTSE-III Optical Limits
  6. GRB061210: Swift/UVOT observations
  7. GRB 061210: Swift XRT analysis - Possible counterparts
  8. GRB 061210: Gemini/GMOS Observations
  9. GRB 061126: Radio Observations
  10. GRB061210: Radio Observations
  11. GRB 061202: Suzaku WAM observation of the prompt emission
  12. GRB 061210, Swift-BAT refined analysis of the SHB
  13. Optical Afterglow observations of GRB 061126
  14. GRB 060926: MASTER: discovery of the optical flare
  15. GRB 061201: UVOT Observations of a Fading Optical Afterglow
  16. GRB 061202: TORTOREM optical upper limits
  17. GRB 061201: VLT optical decay
  18. GRB 061201: SOAR Confirmation of Candidate Afterglow
  19. GRB061202: FRAM early follow-up limit
  20. GRB061202 optical limit by "Pi of the Sky"
  21. GRB061202: optical/NIR observations with REM
  22. GRB061202: Swift/UVOT Upper Limits
  23. GRB 061202, Swift-BAT refined analysis
  24. GRB 061202: Swift detection of a burst
  25. GRB 061201: VLT optical observations
  26. GRB 061201: Initial UVOT Observations
  27. GRB 061201, Swift-BAT refined analysis of the SHB
  28. GRB 061201: Swift detection of a short hard burst
  29. INT+WFC observations of GRB 061126
  30. Swift XRT on-board boresight update
  31. GRB 061126: optical observation
  32. GRB 061126: Tautenburg afterglow observations
  33. GRB061126: Optical afterglow observations from MIRO
  34. GRB061126: Optical afterglow observations from MIRO
  35. GRB 061126 : SDSS Pre-Burst Observations
  36. GRB 061126: Swift-XRT refined analysis
  37. GRB 061126: Swift/UVOT Observations
  38. GRB 061126, Swift-BAT refined analysis
  39. GRB 061126: Early Detection of the IR Afterglow
  40. GRB 061126: Swift/UVOT Afterglow Detection
  41. GRB 061122: Candidate Optical Afterglow
  42. GRB 061121: Ep,i - Eiso correlation
  43. GRB061122: Swift/UVOT Optical Observations
  44. GRB061121: P60 Observations
  45. Radio detection of GRB 061121
  46. GRB061122: Swift-XRT position
  47. INTEGRAL results on GRB 061122
  48. Swift-BAT trigger 239987 is not a GRB
  49. GRB 061121: Swift/UVOT Observations
  50. GRB 061121: Swift-XRT Team Refined Analysis
  51. GRB 061121, Swift-BAT refined analysis
  52. GRB061121, optical observation
  53. GRB 061121: Optical observation at the KANATA 1.5m telescope
  54. GRB 061121: ROTSE-III Confirmation of Optical Counterpart
  55. GRB 061121: Swift detection of a bright burst with an optical counterpart
  56. GRB 060605: NIR Observations
  57. GRB 050915B: optical afterglow
  58. Swift-BAT triggers 238544 and 238546 are not GRBs
  59. Swift/UVOT Upper Limits for GRB061110b
  60. Swift/UVOT Upper Limits for GRB061110a
  61. GRB 061110B, Swift-BAT refined analysis
  62. GRB061110B: Optical observations at Crni Vrh
  63. GRB 061110A: Swift XRT refined analysis
  64. GRB 061110A, Swift-BAT refined analysis
  65. GRB 061110B: TAROT Calern observatory optical observations
  66. GRB 061110B: Swift detection of a burst
  67. GRB 061110: Candidate confirmed
  68. GRB 061110 : Optical afterglow candidate
  69. GRB 061110: ROTSE-III Optical Limits
  70. GRB 061110: Swift detection of a burst
  71. GRB061110A - Optical Non-detection
  72. GRB 061109: optical observation
  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. GRB 061102, XRT refined analysis
  78. GRB061102B: Super-LOTIS observations
  79. GRB 061028: Optical R passband observations
  80. GRB 061102B: Swift detection of a possible burst
  81. GRB 061102, Swift-BAT refined analysis
  82. GRB 061102: Swift detection of a burst
  83. GRB 061028: VLA Observation
  84. GRB 061004: Swift/XRT Astrometry Correction
  85. GRB 060801: Swift/XRT Astrometry Correction
  86. GRB 061028: Futher P200 Observations
  87. GRB 061028: P200 Observations
  88. GRB 061028: SARA upper limit
  89. GRB 061028: z band imaging
  90. GRB061028: XRT refined analysis
  91. GRB 061028: Swift/UVOT Observations
  92. GRB 061028, Swift-BAT refined analysis
  93. GRB 061028: TAROT Calern observatory optical observations
  94. GRB 061028: Swift detection of a burst
  95. GRB 061027, Swift refined analysis of a possible burst
  96. GRB 061027: Swift detection of a possible burst
  97. GRB061025: Swift XRT refined analysis
  98. GRB061025: Swift/UVOT observations
  99. GRB 061025: REM observations
  100. GRB 061025: ROTSE-III Optical Limits

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