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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').
  1. GRB 060124: Swift/UVOT Observation
  2. GRB 060124: Confirmation of the Afterglow
  3. GRB 060124: XRT position
  4. GRB 060124: Optical Afterglow Candidate from Tautenburg
  5. GRB060124, optical observation
  6. GRB 050124 : Kiso Optical limit
  7. GRB 060124: Optical Observations at Tautenburg
  8. GRB 060117: Suzaku WAM observation of the prompt emission
  9. GRB060124:MASTER optical observation
  10. GRB 060111B: Suzaku WAM observation of the prompt emission
  11. GRB 060124: Swift-BAT detection of a burst
  12. GRB 060116: Radio Detection
  13. GRB 060116: MARGE optical observations
  14. GRB 060121: Swift/UVOT upper limits
  15. GRB 060121: Liverpool Telescopes optical limits
  16. GRB 060121: Swift XRT refined analysis
  17. Konus-Wind observation of GRB 060121
  18. GRB 060121: I-band Limits
  19. GRB 060121: Confirmation of Afterglow
  20. GRB 060121: candidate optical counterpart
  21. GRB 060121: Swift XRT refined position
  22. GRB060121: SARA Observations
  23. GRB 060121: optical observations
  24. GRB 060121: Infrared Observations
  25. GRB 060121: optical observations
  26. GRB 060121: Optical imaging
  27. GRB060121 - SDSS pre-burst observations
  28. GRB 060121: A short-hard GRB in a cluster?
  29. GRB 060121 (=H4010): Results of preliminary spectral analysis
  30. GRB 060121: A bright short/hard GRB localized by HETE-2 SXC
  31. GRB 060121: A bright short/hard GRB localized by HETE-2 WXM
  32. HETE Alert 4006: MASTER promt optical limit
  33. GRB 060117: PROMPT Observations
  34. GRB060117 - ATCA 3/6cm radio limits - correction
  35. GRB060117 - ATCA 3/6cm radio limits
  36. GRB 060116: photometric redshift - the farthest GRB?
  37. GRB 060117: pseudo-z from spectral parameters of the prompt emission
  38. Correction to GCN 4542 on GRB 060117
  39. Konus-Wind observation of GRB 060117
  40. GRB 060116: possible I-J dropout
  41. GRB 060116: UKIRT IR Observations
  42. GRB060108: photometric redshift determination
  43. GRB 060117: Refined analysis of the Swift-BAT burst
  44. GRB 060116: PROMPT Observations
  45. GRB 060117: FRAM refined analysis
  46. GRB 060117: FRAM optical afterglow candidate
  47. GRB 060117: nearby galaxy
  48. GRB 060117: Swift-BAT detection of a bright burst
  49. GRB 060116: VLT optical observations
  50. GRB 060116: Refined analysis of the Swift-BAT burst
  51. GRB 060115: PROMPT Observations
  52. GRB 060116: XRT refined analysis
  53. GRB 060116: IR Candidate Afterglow
  54. GRB 060116: Swift/UVOT upper limits
  55. GRB060115: REM observations
  56. GRB 060110: XRT position and analysis
  57. GRB 060116 : Lulin optical limit
  58. GRB 060116: ROTSE-III Optical Limits
  59. GRB060116: XRT position
  60. GRB060116: Faulkes North observation
  61. GRB 060115: absorption redshift
  62. GRB 060116: Swift-BAT detection of a burst
  63. GRB 060115: Refined analysis of the Swift-BAT burst
  64. GRB 060115: OT photometry with MITSuME
  65. GRB 060115: Swift/UVOT upper limits
  66. GRB 060114: REM observations
  67. GRB 060115: Swift XRT refined analysis
  68. GRB 060115: OT finding chart
  69. GRB 060114: Swift/UVOT Observations
  70. GRB060115, optical observation
  71. GRB 060115: MITSuME optical afterglow candidate
  72. GRB 060115: Swift detection of a burst
  73. GRB 060114: Swift XRT upper limit
  74. GRB060114, optical observation
  75. GRB 060114: refined position
  76. GRB 060114: A long GRB detected by INTEGRAL
  77. GRB060114: Faulkes North observation
  78. GRB 060108: IR observations of afterglow
  79. GRB060108: Faulkes North afterglow evidence
  80. GRB 060108: further analysis of VLT images
  81. GRB 060108: Evidence for an XRT Position Offset
  82. GRB 060110: KAIT observations
  83. GRB 060111B: Swift XRT refined analysis
  84. GRB 060111A: refined UVOT anaysis
  85. GRB 060111B: MITSuME detection of optical afterglow
  86. GRB 060111B: TAROT optical observation
  87. GRB060111A: RTT150 optical observations
  88. GRB060111B: RTT150, possible host galaxy
  89. GRB 060111B: Refined analysis of the Swift-BAT burst
  90. GRB 060110: MARGE observations
  91. GRB 060111(a): P60 Observations
  92. GRB 060111B: Gualba observatory limit
  93. GRB 060111B: ROTSE-III Detection of Optical Counterpart Flare
  94. GRB 060111B: Swift detection of a burst
  95. GRB 060111: Swift-BAT Refined Analysis
  96. GRB060111.2:_MASTER optical limit
  97. GRB 060108: VLT K-band observations
  98. GRB 060111: TAROT optical observation
  99. GRB 060111: possible UVOT counterpart
  100. GRB060111 : XRT refined analysis

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