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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-XRT Team refined analysis
  2. GRB 051221B: Swift-XRT Team Refined Analysis
  3. GRB 060219: Partial refined analysis of the Swift-BAT burst
  4. GRB060218: Radio Afterglow Discovery
  5. GRB 060219: Swift-XRT position typo correction
  6. GRB 060218: MDM Redshift
  7. GRB 060219: Swift-XRT position
  8. GRB 060218: optical/nIR observations at La Palma
  9. GRB060219: SDSS pre-burst observations
  10. GRB 060219: Swift-BAT detection of a weak burst
  11. Oddball GRB 060218, transient or GRB?
  12. GRB060218: Swift/XRT Team preliminary analysis of the possible burst
  13. Brightening of the Optical Counterpart of the Possible GRB 060218
  14. GRB 060218: MDM Observations
  15. GRB 060218: Pre-burst detection of a possible host galaxy
  16. GRB 060218A: ROTSE-III Possible Optical Flare
  17. GRB060218: Swift/XRT refined position of a possible burst
  18. Preliminary refined analysis of the Swift-BAT trigger 191157
  19. Further UVOT Observations of the Candidate Optical Afterglow for GRB 060218
  20. GRB 060211B: Swift/UVOT Upper Limits
  21. GRB060218 : SDSS pre-burst observations
  22. GRB 060218: Swift XRT Position
  23. GRB 060218: Swift-BAT detection of a possible burst
  24. GRB 060213: optical afterglow not confirmed
  25. Swift UVOT observations of GRB060213
  26. GRB 060211B: Skynet Observations
  27. GRB 060213: optical afterglow candidate
  28. GRB060213: Swift XRT observations and possible afterglow candidate
  29. GRB 060213: pseudo-z = 3.5 +/- 0.35 from spectral parameters
  30. GRB 060206: Confirmation of Rapid Fading at Optical Wavelengths
  31. GRB060213: MASTER final result
  32. GRB 060211b: WIRO NIR Observations
  33. GRB060213:_MASTER_optical_observation
  34. GRB060206: Swift XRT observations of an unbroken powerlaw decay
  35. Konus-Wind observation of bright hard GRB 060213
  36. GRB 060213: IPN localization
  37. GRB 060210: Radio Observations
  38. GRB 060211a: WIRO NIR Observations
  39. GRB060211B: REM optical and NIR observations
  40. GRB 060211B: BAT detects no additional burst emission beyond T + 122 sec
  41. GRB 060211A: Further refined analysis of the Swift burst
  42. GRB060121: optical observations
  43. GRB060110: optical observations
  44. GRB060105: optical observations
  45. GRB 060210: ARC NIR Detection of Afterglow and Possible Host Galaxy
  46. GRB 060211b: P60 Observations
  47. GRB 060211A: Partial refined analysis on the Swift-BAT burst
  48. GRB 060206: SOAR Detections
  49. GRB 050826: Optical Afterglow and Host Galaxy
  50. GRB 060210: Further refined analysis of the Swift-BAT burst
  51. GRB 060211B: Swift/BAT refined analysis
  52. GRB060210: Swift/UVOT Upper Limits
  53. GRB 060211B: Swift-XRT Team refined analysis
  54. GRB060211b: optical observation
  55. GRB060211B: Swift/XRT position
  56. GRB 060210: Optical Observations
  57. GRB060211.7: MASTER_optical_observation under the snow
  58. GRB 060211A: Swift XRT Team Refined Analysis
  59. GRB 060211B: Swift-BAT detection of a burst
  60. GRB060211: Faulkes North observation
  61. GRB 060211: ROTSE-III Optical Limits
  62. GRB 060211: Swift detection of a long burst
  63. GRB 060210: Refined analysis of the Swift-BAT burst
  64. GRB060210: Swift XRT Refined Analysis
  65. GRB060206, optical observations
  66. GRB 060210 : Xinglong and Lulin optical limit
  67. GRB060210: Optical Observations
  68. GRB060210: Gemini absorption spectroscopy
  69. GRB060210: Early Optical Observations
  70. GRB 060210: optical evolution
  71. GRB060210:Faulkes Telescope North Afterglow Confirmation
  72. GRB 060210: candidate afterglow
  73. GRB 060210: Swift detection of a burst
  74. GRB060210: Optical afterglow
  75. GRB 060206: Swift/UVOT Observations
  76. Swift-BAT trigger 180931 is not a GRB
  77. GRB060209: RTT150 optical observations
  78. GRB 060209 : TAROT optical observation
  79. GRB060209A: MASTER optical observation
  80. GRB 060209(?): Swift-BAT detection of a possible burst
  81. GRB 060206: near-infrared observations (JK' imaging)
  82. GRB 060206: WSRT Radio Observations
  83. GRB 060203: Swift/UVOT upper limits
  84. GRB 060206: TTT Observations
  85. GRB 060206: More PROMPT Detections
  86. GRB 060121 : WIDGET Pre-trigger limit
  87. GRB 060206: Tenagra II Observations
  88. GRB 060206: PROMPT Detections
  89. Retraction of orphan GRB afterglow candidate
  90. GRB060204a: Swift XRT Source is not GRB Afterglow
  91. GRB 060206: optical observations at Asiago
  92. Orphan GRB Afterglow candidate
  93. GRB 060204b: pseudo-z from spectral parameters of the prompt emission
  94. GRB 060206: Subaru/FOCAS optical spectroscopy
  95. GRB 060206: IR Detection of the Afterglow
  96. GRB 060206: Lick 3m Spectroscopy
  97. GRB 060204A: ROSAT Pointing
  98. GRB 060206: Super-LOTIS observations
  99. GRB060204A: Swift/UVOT observations
  100. GRB 060206: Swift-BAT refined analysis

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