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

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