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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. Preliminary refined analysis of the Swift-BAT trigger 191157
  2. Further UVOT Observations of the Candidate Optical Afterglow for GRB 060218
  3. GRB 060211B: Swift/UVOT Upper Limits
  4. GRB060218 : SDSS pre-burst observations
  5. GRB 060218: Swift XRT Position
  6. GRB 060218: Swift-BAT detection of a possible burst
  7. GRB 060213: optical afterglow not confirmed
  8. Swift UVOT observations of GRB060213
  9. GRB 060211B: Skynet Observations
  10. GRB 060213: optical afterglow candidate
  11. GRB060213: Swift XRT observations and possible afterglow candidate
  12. GRB 060213: pseudo-z = 3.5 +/- 0.35 from spectral parameters
  13. GRB 060206: Confirmation of Rapid Fading at Optical Wavelengths
  14. GRB060213: MASTER final result
  15. GRB 060211b: WIRO NIR Observations
  16. GRB060213:_MASTER_optical_observation
  17. GRB060206: Swift XRT observations of an unbroken powerlaw decay
  18. Konus-Wind observation of bright hard GRB 060213
  19. GRB 060213: IPN localization
  20. GRB 060210: Radio Observations
  21. GRB 060211a: WIRO NIR Observations
  22. GRB060211B: REM optical and NIR observations
  23. GRB 060211B: BAT detects no additional burst emission beyond T + 122 sec
  24. GRB 060211A: Further refined analysis of the Swift burst
  25. GRB060121: optical observations
  26. GRB060110: optical observations
  27. GRB060105: optical observations
  28. GRB 060210: ARC NIR Detection of Afterglow and Possible Host Galaxy
  29. GRB 060211b: P60 Observations
  30. GRB 060211A: Partial refined analysis on the Swift-BAT burst
  31. GRB 060206: SOAR Detections
  32. GRB 050826: Optical Afterglow and Host Galaxy
  33. GRB 060210: Further refined analysis of the Swift-BAT burst
  34. GRB 060211B: Swift/BAT refined analysis
  35. GRB060210: Swift/UVOT Upper Limits
  36. GRB 060211B: Swift-XRT Team refined analysis
  37. GRB060211b: optical observation
  38. GRB060211B: Swift/XRT position
  39. GRB 060210: Optical Observations
  40. GRB060211.7: MASTER_optical_observation under the snow
  41. GRB 060211A: Swift XRT Team Refined Analysis
  42. GRB 060211B: Swift-BAT detection of a burst
  43. GRB060211: Faulkes North observation
  44. GRB 060211: ROTSE-III Optical Limits
  45. GRB 060211: Swift detection of a long burst
  46. GRB 060210: Refined analysis of the Swift-BAT burst
  47. GRB060210: Swift XRT Refined Analysis
  48. GRB060206, optical observations
  49. GRB 060210 : Xinglong and Lulin optical limit
  50. GRB060210: Optical Observations
  51. GRB060210: Gemini absorption spectroscopy
  52. GRB060210: Early Optical Observations
  53. GRB 060210: optical evolution
  54. GRB060210:Faulkes Telescope North Afterglow Confirmation
  55. GRB 060210: candidate afterglow
  56. GRB 060210: Swift detection of a burst
  57. GRB060210: Optical afterglow
  58. GRB 060206: Swift/UVOT Observations
  59. Swift-BAT trigger 180931 is not a GRB
  60. GRB060209: RTT150 optical observations
  61. GRB 060209 : TAROT optical observation
  62. GRB060209A: MASTER optical observation
  63. GRB 060209(?): Swift-BAT detection of a possible burst
  64. GRB 060206: near-infrared observations (JK' imaging)
  65. GRB 060206: WSRT Radio Observations
  66. GRB 060203: Swift/UVOT upper limits
  67. GRB 060206: TTT Observations
  68. GRB 060206: More PROMPT Detections
  69. GRB 060121 : WIDGET Pre-trigger limit
  70. GRB 060206: Tenagra II Observations
  71. GRB 060206: PROMPT Detections
  72. Retraction of orphan GRB afterglow candidate
  73. GRB060204a: Swift XRT Source is not GRB Afterglow
  74. GRB 060206: optical observations at Asiago
  75. Orphan GRB Afterglow candidate
  76. GRB 060204b: pseudo-z from spectral parameters of the prompt emission
  77. GRB 060206: Subaru/FOCAS optical spectroscopy
  78. GRB 060206: IR Detection of the Afterglow
  79. GRB 060206: Lick 3m Spectroscopy
  80. GRB 060204A: ROSAT Pointing
  81. GRB 060206: Super-LOTIS observations
  82. GRB060204A: Swift/UVOT observations
  83. GRB 060206: Swift-BAT refined analysis
  84. GRB 060206 : Lulin optical observations
  85. GRB060206: SDSS Pre-Burst Observations
  86. GRB060206: Swift XRT Refined Analysis
  87. GRB060206: Liverpool Telescope observation
  88. GRB 060206: Spectroscopic Redshift
  89. GRB060206: P60 Optical Observations
  90. GRB 060206: KAIT observations
  91. GRB060206: Swift XRT Position
  92. GRB060206: SARA Detection
  93. GRB 060206: RAPTOR observations of afterglow candidate variability.
  94. GRB 060206: High redshift burst
  95. GRB060204a: Swift XRT Detection of an Afterglow Candidate
  96. GRB060206 - Swift UVOT Confirmation of Optical Afterglow
  97. GRB060206: Optical afterglow
  98. GRB060206: Swift-BAT detection of a burst
  99. GRB 060204C: XRT analysis of Swift J061223.0+701243.9
  100. GRB060203: WHT Z-band observations

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