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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 060219: Swift-BAT detection of a weak burst
  2. Oddball GRB 060218, transient or GRB?
  3. GRB060218: Swift/XRT Team preliminary analysis of the possible burst
  4. Brightening of the Optical Counterpart of the Possible GRB 060218
  5. GRB 060218: MDM Observations
  6. GRB 060218: Pre-burst detection of a possible host galaxy
  7. GRB 060218A: ROTSE-III Possible Optical Flare
  8. GRB060218: Swift/XRT refined position of a possible burst
  9. Preliminary refined analysis of the Swift-BAT trigger 191157
  10. Further UVOT Observations of the Candidate Optical Afterglow for GRB 060218
  11. GRB 060211B: Swift/UVOT Upper Limits
  12. GRB060218 : SDSS pre-burst observations
  13. GRB 060218: Swift XRT Position
  14. GRB 060218: Swift-BAT detection of a possible burst
  15. GRB 060213: optical afterglow not confirmed
  16. Swift UVOT observations of GRB060213
  17. GRB 060211B: Skynet Observations
  18. GRB 060213: optical afterglow candidate
  19. GRB060213: Swift XRT observations and possible afterglow candidate
  20. GRB 060213: pseudo-z = 3.5 +/- 0.35 from spectral parameters
  21. GRB 060206: Confirmation of Rapid Fading at Optical Wavelengths
  22. GRB060213: MASTER final result
  23. GRB 060211b: WIRO NIR Observations
  24. GRB060213:_MASTER_optical_observation
  25. GRB060206: Swift XRT observations of an unbroken powerlaw decay
  26. Konus-Wind observation of bright hard GRB 060213
  27. GRB 060213: IPN localization
  28. GRB 060210: Radio Observations
  29. GRB 060211a: WIRO NIR Observations
  30. GRB060211B: REM optical and NIR observations
  31. GRB 060211B: BAT detects no additional burst emission beyond T + 122 sec
  32. GRB 060211A: Further refined analysis of the Swift burst
  33. GRB060121: optical observations
  34. GRB060110: optical observations
  35. GRB060105: optical observations
  36. GRB 060210: ARC NIR Detection of Afterglow and Possible Host Galaxy
  37. GRB 060211b: P60 Observations
  38. GRB 060211A: Partial refined analysis on the Swift-BAT burst
  39. GRB 060206: SOAR Detections
  40. GRB 050826: Optical Afterglow and Host Galaxy
  41. GRB 060210: Further refined analysis of the Swift-BAT burst
  42. GRB 060211B: Swift/BAT refined analysis
  43. GRB060210: Swift/UVOT Upper Limits
  44. GRB 060211B: Swift-XRT Team refined analysis
  45. GRB060211b: optical observation
  46. GRB060211B: Swift/XRT position
  47. GRB 060210: Optical Observations
  48. GRB060211.7: MASTER_optical_observation under the snow
  49. GRB 060211A: Swift XRT Team Refined Analysis
  50. GRB 060211B: Swift-BAT detection of a burst
  51. GRB060211: Faulkes North observation
  52. GRB 060211: ROTSE-III Optical Limits
  53. GRB 060211: Swift detection of a long burst
  54. GRB 060210: Refined analysis of the Swift-BAT burst
  55. GRB060210: Swift XRT Refined Analysis
  56. GRB060206, optical observations
  57. GRB 060210 : Xinglong and Lulin optical limit
  58. GRB060210: Optical Observations
  59. GRB060210: Gemini absorption spectroscopy
  60. GRB060210: Early Optical Observations
  61. GRB 060210: optical evolution
  62. GRB060210:Faulkes Telescope North Afterglow Confirmation
  63. GRB 060210: candidate afterglow
  64. GRB 060210: Swift detection of a burst
  65. GRB060210: Optical afterglow
  66. GRB 060206: Swift/UVOT Observations
  67. Swift-BAT trigger 180931 is not a GRB
  68. GRB060209: RTT150 optical observations
  69. GRB 060209 : TAROT optical observation
  70. GRB060209A: MASTER optical observation
  71. GRB 060209(?): Swift-BAT detection of a possible burst
  72. GRB 060206: near-infrared observations (JK' imaging)
  73. GRB 060206: WSRT Radio Observations
  74. GRB 060203: Swift/UVOT upper limits
  75. GRB 060206: TTT Observations
  76. GRB 060206: More PROMPT Detections
  77. GRB 060121 : WIDGET Pre-trigger limit
  78. GRB 060206: Tenagra II Observations
  79. GRB 060206: PROMPT Detections
  80. Retraction of orphan GRB afterglow candidate
  81. GRB060204a: Swift XRT Source is not GRB Afterglow
  82. GRB 060206: optical observations at Asiago
  83. Orphan GRB Afterglow candidate
  84. GRB 060204b: pseudo-z from spectral parameters of the prompt emission
  85. GRB 060206: Subaru/FOCAS optical spectroscopy
  86. GRB 060206: IR Detection of the Afterglow
  87. GRB 060206: Lick 3m Spectroscopy
  88. GRB 060204A: ROSAT Pointing
  89. GRB 060206: Super-LOTIS observations
  90. GRB060204A: Swift/UVOT observations
  91. GRB 060206: Swift-BAT refined analysis
  92. GRB 060206 : Lulin optical observations
  93. GRB060206: SDSS Pre-Burst Observations
  94. GRB060206: Swift XRT Refined Analysis
  95. GRB060206: Liverpool Telescope observation
  96. GRB 060206: Spectroscopic Redshift
  97. GRB060206: P60 Optical Observations
  98. GRB 060206: KAIT observations
  99. GRB060206: Swift XRT Position
  100. GRB060206: SARA Detection

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