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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"
  1. GRB 060121: A bright short/hard GRB localized by HETE-2 WXM
  2. HETE Alert 4006: MASTER promt optical limit
  3. GRB 060117: PROMPT Observations
  4. GRB060117 - ATCA 3/6cm radio limits - correction
  5. GRB060117 - ATCA 3/6cm radio limits
  6. GRB 060116: photometric redshift - the farthest GRB?
  7. GRB 060117: pseudo-z from spectral parameters of the prompt emission
  8. Correction to GCN 4542 on GRB 060117
  9. Konus-Wind observation of GRB 060117
  10. GRB 060116: possible I-J dropout
  11. GRB 060116: UKIRT IR Observations
  12. GRB060108: photometric redshift determination
  13. GRB 060117: Refined analysis of the Swift-BAT burst
  14. GRB 060116: PROMPT Observations
  15. GRB 060117: FRAM refined analysis
  16. GRB 060117: FRAM optical afterglow candidate
  17. GRB 060117: nearby galaxy
  18. GRB 060117: Swift-BAT detection of a bright burst
  19. GRB 060116: VLT optical observations
  20. GRB 060116: Refined analysis of the Swift-BAT burst
  21. GRB 060115: PROMPT Observations
  22. GRB 060116: XRT refined analysis
  23. GRB 060116: IR Candidate Afterglow
  24. GRB 060116: Swift/UVOT upper limits
  25. GRB060115: REM observations
  26. GRB 060110: XRT position and analysis
  27. GRB 060116 : Lulin optical limit
  28. GRB 060116: ROTSE-III Optical Limits
  29. GRB060116: XRT position
  30. GRB060116: Faulkes North observation
  31. GRB 060115: absorption redshift
  32. GRB 060116: Swift-BAT detection of a burst
  33. GRB 060115: Refined analysis of the Swift-BAT burst
  34. GRB 060115: OT photometry with MITSuME
  35. GRB 060115: Swift/UVOT upper limits
  36. GRB 060114: REM observations
  37. GRB 060115: Swift XRT refined analysis
  38. GRB 060115: OT finding chart
  39. GRB 060114: Swift/UVOT Observations
  40. GRB060115, optical observation
  41. GRB 060115: MITSuME optical afterglow candidate
  42. GRB 060115: Swift detection of a burst
  43. GRB 060114: Swift XRT upper limit
  44. GRB060114, optical observation
  45. GRB 060114: refined position
  46. GRB 060114: A long GRB detected by INTEGRAL
  47. GRB060114: Faulkes North observation
  48. GRB 060108: IR observations of afterglow
  49. GRB060108: Faulkes North afterglow evidence
  50. GRB 060108: further analysis of VLT images
  51. GRB 060108: Evidence for an XRT Position Offset
  52. GRB 060110: KAIT observations
  53. GRB 060111B: Swift XRT refined analysis
  54. GRB 060111A: refined UVOT anaysis
  55. GRB 060111B: MITSuME detection of optical afterglow
  56. GRB 060111B: TAROT optical observation
  57. GRB060111A: RTT150 optical observations
  58. GRB060111B: RTT150, possible host galaxy
  59. GRB 060111B: Refined analysis of the Swift-BAT burst
  60. GRB 060110: MARGE observations
  61. GRB 060111(a): P60 Observations
  62. GRB 060111B: Gualba observatory limit
  63. GRB 060111B: ROTSE-III Detection of Optical Counterpart Flare
  64. GRB 060111B: Swift detection of a burst
  65. GRB 060111: Swift-BAT Refined Analysis
  66. GRB060111.2:_MASTER optical limit
  67. GRB 060108: VLT K-band observations
  68. GRB 060111: TAROT optical observation
  69. GRB 060111: possible UVOT counterpart
  70. GRB060111 : XRT refined analysis
  71. GRB 060111: ROTSE-III Optical Limits
  72. GRB 060111: Swift detection of a burst
  73. GRB 060110: Mitsume optical observations
  74. GRB 060110: Swift-BAT refined analysis
  75. GRB 060109: Swift-BAT refined analysis
  76. GRB 060108: z-band imaging from Gemini-North
  77. GRB 060110a: RAPTOR detection of early optical emission.
  78. GRB 060110: UKIRT K-band observations
  79. GRB 060110: ROTSE-III Confirmation of Optical Counterpart
  80. GRB 060110: IR Candidate Afterglow
  81. GRB060110, optical observation
  82. GRB 060110: Super-LOTIS observations
  83. GRB 060110: Optical observation
  84. GRB 060110: Correction
  85. Correction to GRB 060109 XRT analysis
  86. GRB 050110: IR Observations
  87. GRB 060110: Optical limit
  88. GRB 060110: Swift-BAT detection of a burst
  89. GRB 060109: Refined Swift-XRT analysis
  90. GRB 060109: Swift/UVOT upper limits
  91. GRB060109, optical observation
  92. GRB 060108: ISAS early observations and near IR upper limit
  93. GRB060108: P200 Ks Observations
  94. GRB 060108: early UKIRT K-band observations
  95. Swift UVOT correction to GCN 4455
  96. GRB 060109: Swift Detection of a long burst
  97. GRB 060108: a dark burst?
  98. GRB 060108: Refined XRT analysis
  99. GRB 060108: VLT J-band observations
  100. GRB 060108: Mitsume optical observations

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