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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"

28085 results found.

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

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