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

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