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

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