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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 060124: XRT refined analysis
  2. GRB 060124: R band Observations
  3. GRB 060124 : Optical observation at Xinglong and Kiso
  4. GRB060124: optical observations at Asiago
  5. GRB 060124: Extremely long burst, Swift-BAT refined analysis
  6. GRB060123: SDSS pre-burst observations
  7. GRB 060123: Swift detection of a very long, faint burst
  8. GRB 060116: Further analysis of VLT photometry and optical spectroscopy
  9. GRB 060121: OHP optical limits
  10. GRB 060124: TAROT optical limits
  11. GRB 060124: Swift/UVOT Observation
  12. GRB 060124: Confirmation of the Afterglow
  13. GRB 060124: XRT position
  14. GRB 060124: Optical Afterglow Candidate from Tautenburg
  15. GRB060124, optical observation
  16. GRB 050124 : Kiso Optical limit
  17. GRB 060124: Optical Observations at Tautenburg
  18. GRB 060117: Suzaku WAM observation of the prompt emission
  19. GRB060124:MASTER optical observation
  20. GRB 060111B: Suzaku WAM observation of the prompt emission
  21. GRB 060124: Swift-BAT detection of a burst
  22. GRB 060116: Radio Detection
  23. GRB 060116: MARGE optical observations
  24. GRB 060121: Swift/UVOT upper limits
  25. GRB 060121: Liverpool Telescopes optical limits
  26. GRB 060121: Swift XRT refined analysis
  27. Konus-Wind observation of GRB 060121
  28. GRB 060121: I-band Limits
  29. GRB 060121: Confirmation of Afterglow
  30. GRB 060121: candidate optical counterpart
  31. GRB 060121: Swift XRT refined position
  32. GRB060121: SARA Observations
  33. GRB 060121: optical observations
  34. GRB 060121: Infrared Observations
  35. GRB 060121: optical observations
  36. GRB 060121: Optical imaging
  37. GRB060121 - SDSS pre-burst observations
  38. GRB 060121: A short-hard GRB in a cluster?
  39. GRB 060121 (=H4010): Results of preliminary spectral analysis
  40. GRB 060121: A bright short/hard GRB localized by HETE-2 SXC
  41. GRB 060121: A bright short/hard GRB localized by HETE-2 WXM
  42. HETE Alert 4006: MASTER promt optical limit
  43. GRB 060117: PROMPT Observations
  44. GRB060117 - ATCA 3/6cm radio limits - correction
  45. GRB060117 - ATCA 3/6cm radio limits
  46. GRB 060116: photometric redshift - the farthest GRB?
  47. GRB 060117: pseudo-z from spectral parameters of the prompt emission
  48. Correction to GCN 4542 on GRB 060117
  49. Konus-Wind observation of GRB 060117
  50. GRB 060116: possible I-J dropout
  51. GRB 060116: UKIRT IR Observations
  52. GRB060108: photometric redshift determination
  53. GRB 060117: Refined analysis of the Swift-BAT burst
  54. GRB 060116: PROMPT Observations
  55. GRB 060117: FRAM refined analysis
  56. GRB 060117: FRAM optical afterglow candidate
  57. GRB 060117: nearby galaxy
  58. GRB 060117: Swift-BAT detection of a bright burst
  59. GRB 060116: VLT optical observations
  60. GRB 060116: Refined analysis of the Swift-BAT burst
  61. GRB 060115: PROMPT Observations
  62. GRB 060116: XRT refined analysis
  63. GRB 060116: IR Candidate Afterglow
  64. GRB 060116: Swift/UVOT upper limits
  65. GRB060115: REM observations
  66. GRB 060110: XRT position and analysis
  67. GRB 060116 : Lulin optical limit
  68. GRB 060116: ROTSE-III Optical Limits
  69. GRB060116: XRT position
  70. GRB060116: Faulkes North observation
  71. GRB 060115: absorption redshift
  72. GRB 060116: Swift-BAT detection of a burst
  73. GRB 060115: Refined analysis of the Swift-BAT burst
  74. GRB 060115: OT photometry with MITSuME
  75. GRB 060115: Swift/UVOT upper limits
  76. GRB 060114: REM observations
  77. GRB 060115: Swift XRT refined analysis
  78. GRB 060115: OT finding chart
  79. GRB 060114: Swift/UVOT Observations
  80. GRB060115, optical observation
  81. GRB 060115: MITSuME optical afterglow candidate
  82. GRB 060115: Swift detection of a burst
  83. GRB 060114: Swift XRT upper limit
  84. GRB060114, optical observation
  85. GRB 060114: refined position
  86. GRB 060114: A long GRB detected by INTEGRAL
  87. GRB060114: Faulkes North observation
  88. GRB 060108: IR observations of afterglow
  89. GRB060108: Faulkes North afterglow evidence
  90. GRB 060108: further analysis of VLT images
  91. GRB 060108: Evidence for an XRT Position Offset
  92. GRB 060110: KAIT observations
  93. GRB 060111B: Swift XRT refined analysis
  94. GRB 060111A: refined UVOT anaysis
  95. GRB 060111B: MITSuME detection of optical afterglow
  96. GRB 060111B: TAROT optical observation
  97. GRB060111A: RTT150 optical observations
  98. GRB060111B: RTT150, possible host galaxy
  99. GRB 060111B: Refined analysis of the Swift-BAT burst
  100. GRB 060110: MARGE observations

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