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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: ART optical limits during the burst
  2. GRB060123: Optical and IR Imaging
  3. GRB 060123: P200 Observations
  4. GRB 060124: Keck optical spectrum
  5. GRB 060124: Keck Absorption Redshift
  6. GRB 060124: MDM Optical Spectrum
  7. GRB 060124: XRT refined analysis
  8. GRB 060124: R band Observations
  9. GRB 060124 : Optical observation at Xinglong and Kiso
  10. GRB060124: optical observations at Asiago
  11. GRB 060124: Extremely long burst, Swift-BAT refined analysis
  12. GRB060123: SDSS pre-burst observations
  13. GRB 060123: Swift detection of a very long, faint burst
  14. GRB 060116: Further analysis of VLT photometry and optical spectroscopy
  15. GRB 060121: OHP optical limits
  16. GRB 060124: TAROT optical limits
  17. GRB 060124: Swift/UVOT Observation
  18. GRB 060124: Confirmation of the Afterglow
  19. GRB 060124: XRT position
  20. GRB 060124: Optical Afterglow Candidate from Tautenburg
  21. GRB060124, optical observation
  22. GRB 050124 : Kiso Optical limit
  23. GRB 060124: Optical Observations at Tautenburg
  24. GRB 060117: Suzaku WAM observation of the prompt emission
  25. GRB060124:MASTER optical observation
  26. GRB 060111B: Suzaku WAM observation of the prompt emission
  27. GRB 060124: Swift-BAT detection of a burst
  28. GRB 060116: Radio Detection
  29. GRB 060116: MARGE optical observations
  30. GRB 060121: Swift/UVOT upper limits
  31. GRB 060121: Liverpool Telescopes optical limits
  32. GRB 060121: Swift XRT refined analysis
  33. Konus-Wind observation of GRB 060121
  34. GRB 060121: I-band Limits
  35. GRB 060121: Confirmation of Afterglow
  36. GRB 060121: candidate optical counterpart
  37. GRB 060121: Swift XRT refined position
  38. GRB060121: SARA Observations
  39. GRB 060121: optical observations
  40. GRB 060121: Infrared Observations
  41. GRB 060121: optical observations
  42. GRB 060121: Optical imaging
  43. GRB060121 - SDSS pre-burst observations
  44. GRB 060121: A short-hard GRB in a cluster?
  45. GRB 060121 (=H4010): Results of preliminary spectral analysis
  46. GRB 060121: A bright short/hard GRB localized by HETE-2 SXC
  47. GRB 060121: A bright short/hard GRB localized by HETE-2 WXM
  48. HETE Alert 4006: MASTER promt optical limit
  49. GRB 060117: PROMPT Observations
  50. GRB060117 - ATCA 3/6cm radio limits - correction
  51. GRB060117 - ATCA 3/6cm radio limits
  52. GRB 060116: photometric redshift - the farthest GRB?
  53. GRB 060117: pseudo-z from spectral parameters of the prompt emission
  54. Correction to GCN 4542 on GRB 060117
  55. Konus-Wind observation of GRB 060117
  56. GRB 060116: possible I-J dropout
  57. GRB 060116: UKIRT IR Observations
  58. GRB060108: photometric redshift determination
  59. GRB 060117: Refined analysis of the Swift-BAT burst
  60. GRB 060116: PROMPT Observations
  61. GRB 060117: FRAM refined analysis
  62. GRB 060117: FRAM optical afterglow candidate
  63. GRB 060117: nearby galaxy
  64. GRB 060117: Swift-BAT detection of a bright burst
  65. GRB 060116: VLT optical observations
  66. GRB 060116: Refined analysis of the Swift-BAT burst
  67. GRB 060115: PROMPT Observations
  68. GRB 060116: XRT refined analysis
  69. GRB 060116: IR Candidate Afterglow
  70. GRB 060116: Swift/UVOT upper limits
  71. GRB060115: REM observations
  72. GRB 060110: XRT position and analysis
  73. GRB 060116 : Lulin optical limit
  74. GRB 060116: ROTSE-III Optical Limits
  75. GRB060116: XRT position
  76. GRB060116: Faulkes North observation
  77. GRB 060115: absorption redshift
  78. GRB 060116: Swift-BAT detection of a burst
  79. GRB 060115: Refined analysis of the Swift-BAT burst
  80. GRB 060115: OT photometry with MITSuME
  81. GRB 060115: Swift/UVOT upper limits
  82. GRB 060114: REM observations
  83. GRB 060115: Swift XRT refined analysis
  84. GRB 060115: OT finding chart
  85. GRB 060114: Swift/UVOT Observations
  86. GRB060115, optical observation
  87. GRB 060115: MITSuME optical afterglow candidate
  88. GRB 060115: Swift detection of a burst
  89. GRB 060114: Swift XRT upper limit
  90. GRB060114, optical observation
  91. GRB 060114: refined position
  92. GRB 060114: A long GRB detected by INTEGRAL
  93. GRB060114: Faulkes North observation
  94. GRB 060108: IR observations of afterglow
  95. GRB060108: Faulkes North afterglow evidence
  96. GRB 060108: further analysis of VLT images
  97. GRB 060108: Evidence for an XRT Position Offset
  98. GRB 060110: KAIT observations
  99. GRB 060111B: Swift XRT refined analysis
  100. GRB 060111A: refined UVOT anaysis

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