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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"

27392 results found.

  1. GRB 061217: TAROT Calern observatory optical observations
  2. GRB 061218: TORTOREM optical upper limits
  3. GRB 061218, Swift-BAT refined analysis
  4. GRB061217: VLT NIR observations
  5. GRB 061218, SMARTS optical/IR observations
  6. GRB 061218: REM prompt observations
  7. Swift triggers (#251863) on a possible burst
  8. GRB061217: Swift/UVOT refined analysis.
  9. GRB 061217: optical observations at Calar Alto
  10. GRB061217 - Swift/XRT refined analysis
  11. GRB 061217, Swift-BAT refined analysis
  12. GRB 061217: Magellan Observations
  13. GRB 061217: REM prompt observations
  14. GRB 061217: ROTSE-III Optical Limits
  15. GRB061210: Swift/UVOT observations
  16. GRB 061210: Swift XRT analysis - Possible counterparts
  17. GRB 061210: Gemini/GMOS Observations
  18. GRB 061126: Radio Observations
  19. GRB061210: Radio Observations
  20. GRB 061202: Suzaku WAM observation of the prompt emission
  21. GRB 061210, Swift-BAT refined analysis of the SHB
  22. Optical Afterglow observations of GRB 061126
  23. GRB 060926: MASTER: discovery of the optical flare
  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. GRB061202: optical/NIR observations with REM
  31. GRB061202: Swift/UVOT Upper Limits
  32. GRB 061202, Swift-BAT refined analysis
  33. GRB 061202: Swift detection of a burst
  34. GRB 061201: VLT optical observations
  35. GRB 061201: Initial UVOT Observations
  36. GRB 061201, Swift-BAT refined analysis of the SHB
  37. GRB 061201: Swift detection of a short hard burst
  38. INT+WFC observations of GRB 061126
  39. Swift XRT on-board boresight update
  40. GRB 061126: optical observation
  41. GRB 061126: Tautenburg afterglow observations
  42. GRB061126: Optical afterglow observations from MIRO
  43. GRB061126: Optical afterglow observations from MIRO
  44. GRB 061126 : SDSS Pre-Burst Observations
  45. GRB 061126: Swift-XRT refined analysis
  46. GRB 061126: Swift/UVOT Observations
  47. GRB 061126, Swift-BAT refined analysis
  48. GRB 061126: Early Detection of the IR Afterglow
  49. GRB 061126: Swift/UVOT Afterglow Detection
  50. GRB 061122: Candidate Optical Afterglow
  51. GRB 061121: Ep,i - Eiso correlation
  52. GRB061122: Swift/UVOT Optical Observations
  53. GRB061121: P60 Observations
  54. Radio detection of GRB 061121
  55. GRB061122: Swift-XRT position
  56. INTEGRAL results on GRB 061122
  57. Swift-BAT trigger 239987 is not a GRB
  58. GRB 061121: Swift/UVOT Observations
  59. GRB 061121: Swift-XRT Team Refined Analysis
  60. GRB 061121, Swift-BAT refined analysis
  61. GRB061121, optical observation
  62. GRB 061121: Optical observation at the KANATA 1.5m telescope
  63. GRB 061121: ROTSE-III Confirmation of Optical Counterpart
  64. GRB 061121: Swift detection of a bright burst with an optical counterpart
  65. GRB 060605: NIR Observations
  66. GRB 050915B: optical afterglow
  67. Swift-BAT triggers 238544 and 238546 are not GRBs
  68. Swift/UVOT Upper Limits for GRB061110b
  69. Swift/UVOT Upper Limits for GRB061110a
  70. GRB 061110B, Swift-BAT refined analysis
  71. GRB061110B: Optical observations at Crni Vrh
  72. GRB 061110A: Swift XRT refined analysis
  73. GRB 061110A, Swift-BAT refined analysis
  74. GRB 061110B: TAROT Calern observatory optical observations
  75. GRB 061110B: Swift detection of a burst
  76. GRB 061110: Candidate confirmed
  77. GRB 061110 : Optical afterglow candidate
  78. GRB 061110: ROTSE-III Optical Limits
  79. GRB 061110: Swift detection of a burst
  80. GRB061110A - Optical Non-detection
  81. GRB 061109: optical observation
  82. GRB 061109: TAROT Calern observatory optical observations
  83. GRB 061027: TAROT La Silla observatory optical observations
  84. GRB 061028: Swift/XRT Astrometry Correction
  85. GRB 061102: Swift/UVOT Magnitude Upper Limits
  86. GRB 061102, XRT refined analysis
  87. GRB061102B: Super-LOTIS observations
  88. GRB 061028: Optical R passband observations
  89. GRB 061102B: Swift detection of a possible burst
  90. GRB 061102, Swift-BAT refined analysis
  91. GRB 061102: Swift detection of a burst
  92. GRB 061028: VLA Observation
  93. GRB 061004: Swift/XRT Astrometry Correction
  94. GRB 060801: Swift/XRT Astrometry Correction
  95. GRB 061028: Futher P200 Observations
  96. GRB 061028: P200 Observations
  97. GRB 061028: SARA upper limit
  98. GRB 061028: z band imaging
  99. GRB061028: XRT refined analysis
  100. GRB 061028: Swift/UVOT Observations

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