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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 060213: optical afterglow candidate
  2. GRB060213: Swift XRT observations and possible afterglow candidate
  3. GRB 060213: pseudo-z = 3.5 +/- 0.35 from spectral parameters
  4. GRB 060206: Confirmation of Rapid Fading at Optical Wavelengths
  5. GRB060213: MASTER final result
  6. GRB 060211b: WIRO NIR Observations
  7. GRB060213:_MASTER_optical_observation
  8. GRB060206: Swift XRT observations of an unbroken powerlaw decay
  9. Konus-Wind observation of bright hard GRB 060213
  10. GRB 060213: IPN localization
  11. GRB 060210: Radio Observations
  12. GRB 060211a: WIRO NIR Observations
  13. GRB060211B: REM optical and NIR observations
  14. GRB 060211B: BAT detects no additional burst emission beyond T + 122 sec
  15. GRB 060211A: Further refined analysis of the Swift burst
  16. GRB060121: optical observations
  17. GRB060110: optical observations
  18. GRB060105: optical observations
  19. GRB 060210: ARC NIR Detection of Afterglow and Possible Host Galaxy
  20. GRB 060211b: P60 Observations
  21. GRB 060211A: Partial refined analysis on the Swift-BAT burst
  22. GRB 060206: SOAR Detections
  23. GRB 050826: Optical Afterglow and Host Galaxy
  24. GRB 060210: Further refined analysis of the Swift-BAT burst
  25. GRB 060211B: Swift/BAT refined analysis
  26. GRB060210: Swift/UVOT Upper Limits
  27. GRB 060211B: Swift-XRT Team refined analysis
  28. GRB060211b: optical observation
  29. GRB060211B: Swift/XRT position
  30. GRB 060210: Optical Observations
  31. GRB060211.7: MASTER_optical_observation under the snow
  32. GRB 060211A: Swift XRT Team Refined Analysis
  33. GRB 060211B: Swift-BAT detection of a burst
  34. GRB060211: Faulkes North observation
  35. GRB 060211: ROTSE-III Optical Limits
  36. GRB 060211: Swift detection of a long burst
  37. GRB 060210: Refined analysis of the Swift-BAT burst
  38. GRB060210: Swift XRT Refined Analysis
  39. GRB060206, optical observations
  40. GRB 060210 : Xinglong and Lulin optical limit
  41. GRB060210: Optical Observations
  42. GRB060210: Gemini absorption spectroscopy
  43. GRB060210: Early Optical Observations
  44. GRB 060210: optical evolution
  45. GRB060210:Faulkes Telescope North Afterglow Confirmation
  46. GRB 060210: candidate afterglow
  47. GRB 060210: Swift detection of a burst
  48. GRB060210: Optical afterglow
  49. GRB 060206: Swift/UVOT Observations
  50. Swift-BAT trigger 180931 is not a GRB
  51. GRB060209: RTT150 optical observations
  52. GRB 060209 : TAROT optical observation
  53. GRB060209A: MASTER optical observation
  54. GRB 060209(?): Swift-BAT detection of a possible burst
  55. GRB 060206: near-infrared observations (JK' imaging)
  56. GRB 060206: WSRT Radio Observations
  57. GRB 060203: Swift/UVOT upper limits
  58. GRB 060206: TTT Observations
  59. GRB 060206: More PROMPT Detections
  60. GRB 060121 : WIDGET Pre-trigger limit
  61. GRB 060206: Tenagra II Observations
  62. GRB 060206: PROMPT Detections
  63. Retraction of orphan GRB afterglow candidate
  64. GRB060204a: Swift XRT Source is not GRB Afterglow
  65. GRB 060206: optical observations at Asiago
  66. Orphan GRB Afterglow candidate
  67. GRB 060204b: pseudo-z from spectral parameters of the prompt emission
  68. GRB 060206: Subaru/FOCAS optical spectroscopy
  69. GRB 060206: IR Detection of the Afterglow
  70. GRB 060206: Lick 3m Spectroscopy
  71. GRB 060204A: ROSAT Pointing
  72. GRB 060206: Super-LOTIS observations
  73. GRB060204A: Swift/UVOT observations
  74. GRB 060206: Swift-BAT refined analysis
  75. GRB 060206 : Lulin optical observations
  76. GRB060206: SDSS Pre-Burst Observations
  77. GRB060206: Swift XRT Refined Analysis
  78. GRB060206: Liverpool Telescope observation
  79. GRB 060206: Spectroscopic Redshift
  80. GRB060206: P60 Optical Observations
  81. GRB 060206: KAIT observations
  82. GRB060206: Swift XRT Position
  83. GRB060206: SARA Detection
  84. GRB 060206: RAPTOR observations of afterglow candidate variability.
  85. GRB 060206: High redshift burst
  86. GRB060204a: Swift XRT Detection of an Afterglow Candidate
  87. GRB060206 - Swift UVOT Confirmation of Optical Afterglow
  88. GRB060206: Optical afterglow
  89. GRB060206: Swift-BAT detection of a burst
  90. GRB 060204C: XRT analysis of Swift J061223.0+701243.9
  91. GRB060203: WHT Z-band observations
  92. BAT GRB 060204C is probably not a GRB
  93. GRB060204C: optical observation
  94. GRB 060204B: BVRi-band detections of optical afterglow
  95. GRB 060204A: Swift XRT upper limit
  96. GRB 060204A: FRAM optical observations
  97. GRB060204B: Swift/UVOT refined analysis
  98. GRB 060204C: optical observations
  99. Swift XRT Observation of GRB 060204C
  100. GRB 060204B: Swift-BAT refined analysis

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